Polyether urethane foam produced with cyano-ether polysiloxane-polyoxyalkylene copolymers

ABSTRACT

Organosilicone compositions are provided which comprise polysiloxane-polyoxyalkylene copolymers containing monofunctional siloxy units (M o ) and, for every two moles of M o , an average of between about 10 and about 200 difunctional dialkylsiloxy units, an average of between about 2 and about 100 silicon-bonded cyano-bearing ether groups (Q) having the formula, --(O) q  R&#39;OR&#34;CN, wherein q is zero or one, R&#39; is bivalent alkylene of 3 to 8 carbon atoms and R&#34; is bivalent alkylene of 2 to 4 carbon atoms, and an average of between about 2 and about 30 silicon-bonded, organic-capped polyoxyalkylene blocks (E), the polyoxyalkylene content of said copolymers being constituted of between about 20 and about 65 weight percent of oxyethylene units, said M o  units having at least two alkyls bonded to the respective silicon atoms thereof, the remaining organic group of M o  being alkyl, Q or E, said copolymers also containing difunctional monoalkylsiloxy units the remaining organic group bonded to the respective silicon atoms thereof being Q or E. The polymers of the invention are effective stabilizers of flexible polyether polyol-based polyurethane foam and offer particular advantage in the formation of flame-retarded foam.

This is a division of application Ser. No. 536,885, filed Dec. 27, 1974,now U.S. Pat. No. 3,979,420, granted Sept. 7, 1976.

BACKGROUND OF THE INVENTION

The present invention relates to novel organosilicone polymers and theiruse in the manufacture of urethane cellular products, particularlyflame-retarded flexible polyether polyol-based urethane foams.

It is well known that the urethane linkages of urethane foams are formedby the exothermic reaction of a polyfunctional isocyanate and apolyfunctional active hydrogen-containing compound in the presence of acatalyst, and that the cellular structure of the foam is provided by gasevolution and expansion during the urethane-forming reaction. Inaccordance with the "one-shot process" which is the most widely usedindustrial technique, direct reaction is effected between all of the rawmaterials which include the polyisocyanate, the activehydrogen-containing compound, the catalyst system, blowing agent andsurfactant. A major function of the surfactant is to stabilize theurethane foam, that is, prevent collapse of the foam until the foamedproduct has developed sufficient gel strength to become self-supporting.

It is also well known that suitable active hydrogen-containing compoundsinclude polyether polyols and polyester polyols. From the standpoint oftheir chemical structure, therefore, urethanes are usually classified aspolyether and polyester urethanes, respectively. Urethane foams alsodiffer with respect to their physical structure and, from thisstandpoint, are generally classified as flexible, semiflexible or rigidfoams.

Although certain techniques of urethane manufacture such as the"one-shot process" and certain components of the foam formulation suchas the polyisocyanates, amine catalyst and blowing agent, are generallyuseful, a specific problem associated with the production of aparticular type of urethane foam and the solution thereto are oftenpeculiar to the chemical and physical structure of the desired foamedproduct. In particular, the efficacy of the foam stabilizer is usuallyselective with respect to the formation of a particular type of foam.One factor to be considered in the evaluation of stabilizing efficacy issurfactant potency which is reflected by two types of measurements. Oneis the measured original height to which the foam rises as it is beingformed. From this standpoint, the greater the foam rise, the more potentis the surfactant. The second potency measurement is concerned with theability of the surfactant to maintain the original height of the foamonce it has formed. Foams produced with surfactants which have goodpotency in this second respect undergo a minimum of settling or "topcollapse" which may otherwise contribute to split formation and otherfoam defects.

The search for improved surfactants for stabilization of polyurethanefoams is further complicated by the tendency of such foams to ignitereadily and burn and the need to reduce their flammability. Thischaracteristic is particularly ojectionable in the case of flexiblepolyurethane foams in view of the use of such foams in many applicationswhere fire is especially hazardous such as their use in automotive seatcushions and household furniture cushioning. One approach to reducingflammability of flexible foams is to include a flame-retarding agentsuch as various phosphorus and/or halogen-containing compounds as acomponent of the foam-producing reaction mixture. It is found, however,that surfactants which may otherwise be effective stabilizers of nonflame-retarded as well as flame-retarded foam, may be deficient asstabilizers of flame-retarded foam in that they appear to have anadverse effect on the efficiency of the flame-retardant.

Among the various types of surfactants which have been used to advantagefor stabilization of non flame-retarded flexible polyether-basedurethane foams are polyoxyalkylene-polysiloxane block copolymers whereinsilicon of the siloxane backbone is bonded only to methyl groups and thepolyether portion of the polyoxyalkylene blocks is composed ofoxyethylene and oxypropylene units. Such copolymers include those ofboth the hydrolyzable and non hydrolyzable types, that is, copolymers inwhich the polysiloxane and polyoxyalkylene blocks are linked through--Si--O--C-- and --Si--C-- bonds, respectively. From the standpoint ofpossessing a particularly good combination of potency and processinglatitude in the stabilization of flexible polyether urethane foams, anespecially useful class of non hydrolyzable block copolymers are thosedescribed in Reissue Patent No. 27,541. When used to stabilizepolyether-based foams derived from reaction mixtures containing aflame-retardant, however, copolymers wherein the polysiloxane blocks aresubstituted only with methyl groups including copolymers of thehydrolyzable type, generally provide foams which either do not qualifyas self-extinguishing by flammability test ASTM D-1692-68), or, if soqualified, the burning extent of the foam is at a relatively high level,leaving room for further improvement in this regard.

It is desirable, therefore, and is a primary object of this invention,to provide a new class of poly-siloxane-polyoxyalkylene block copolymerswhich, in addition to good potency as stabilizers of flexiblepolyether-based urethane foam, both non flame-retarded andflame-retarded, have the further advantageous property of allowing forthe formation of flame-retarded foam of relatively low burning extent.

A further object is to provide particular flexible polyether urethanefoam of substantially reduced combustibility and a method for themanufacture of such foam.

Various other objects and advantages of this invention will becomeapparent to those skilled in the art from the accompanying descriptionand disclosure.

As a preface to the description of the present invention, it is notedthat our U.S. Pat. No. 3,846,462 describes and claims a particular classof siloxanepolyoxyalkylene copolymers which possess the advantageousproperty of allowing for formation of flame-retarded polyetherpolyol-based urethane foam of relatively low burning extent. Among othercharacteristics, such copolymers comprise difunctional siloxy units inwhich the two organic radicals bonded to silicon are (1) alkyl and (2)either cyanolkyl such as cyanopropyl [NC--C₃ H₆ --] or cyanoalkoxy suchas cyanopropoxy [NC--C₃ H₆ O--] including combinations of theseparticular two types of silicon-bonded cyano-bearing groups. Our saidpatent, however, does not describe the particular class of novelcopolymers to which the teachings of the present invention pertain.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, a particularclass of cyano-substituted organosiloxane-polyoxyalkylene polymers areprovided which contain chemically combined monofunctional siloxy units(M_(o)) and, for every two moles of M_(o), an average of from about 10to about 200 difunctional dialkylsiloxy units (X), an average of fromabout 2 to about 100 cyano-bearing ether groups (Q) and an average offrom about 2 to about 30 polyoxyalkylene blocks (E), the said Q and Egroups being bonded to silicon of the M_(o) units and/or to silicon ofdifunctional monoalkylsiloxy units (Y and Z, respectively), thepolyoxyalkylene content of the polymers being constituted of betweenabout 20 and about 65 weight percent of oxyethylene units. As indicated,the essential silicon-bonded cyano-bearing ether groups are collectivelyreferred to herein by the symbol "Q" and have the formula, --(O)_(q)--R'OR"--CN, where q is zero or one, R' is bivalent alkylene having from3 to 8 carbon atoms, and R" is bivalent alkylene having from 2 to 4carbon atoms. Thus, when q is zero, Q is cyanoalkoxyalkyl (that is,NC--R"O--R"--) and, when q is one, Q is cyanoalkoxyalkoxy (that is,NC--R"O--R'O--). In either case, the cyano substituent is bonded tocarbon of the alkylene ether group, --R"OR'--, which is in contrast tothe composition of the copolymers described and claimed in ouraforementioned U.S. Pat. No. 3,846,462, in which cyano is present assilicon-bonded cyanoalkyl or cyanoalkoxy.

In the monofunctional siloxy units encompassed by M_(o), the respectivesilicon atoms are bonded to two alkyl groups (R), the thirdsilicon-bonded organic group being the aforesaid cyano-bearing ethergroup (Q), polyoxyalkylene block (E) or alkyl group (R). Thus, includedwithin the scope of M_(o) are monofunctional units having the followingunit formulae which for brevity are also individually referred to hereinas the M, M' and M" units, as shown:

M = (r)₃ siO_(1/2)

M' = (e)(r)₂ siO_(1/2)

M" = (q)(r)₂ siO_(1/2)

In any given polymer composition of the present invention, the M_(o)units may be the same as or different from one another. In thedifunctional siloxy units at least one of the two organic groups bondedto the respective silicon atoms is alkyl and the second silicon-bondedorganic group is either alkyl as in the X units, the aforesaidcyano-bearing ether group (Q) as in the Y units or a polyoxyalkyleneblock (E) as in the Z units. Thus, the difunctional X, Y and Z unitshave the following unit formulae:

X = (r)₂ siO_(2/2)

Y = (q)(r)siO_(2/2)

Z = (e)(r)siO_(2/2)

The organosiloxane-polyoxyalkylene polymers described herein may containany combination or subcombination of the respective siloxy units withinthe scope of M_(o), X, Y and/or Z provided an average of from about 2 toabout 100 cyano-bearing ether groups (Q) and from about 2 to about 30polyoxyalkylene blocks (E) are present, as encompassed by the followingFormula I, ##STR1## wherein: Q, E, R, X, Y and Z have the aforesaidsignificance; each of t, u, v, w, the sum t+u and the sum v+windependently has a value of zero, or one, each of the sum t+w and thesum u+v independently has a value of zero, one or two, it being evidentthat the value of the sum t+u+v+w is also zero, one or two; x has anaverage value from about 10 to about 200; y has an average value fromabout 2 to about 100; and z has an average value from about 2 to about30. It is evident from Formula I that x, y-(t+w) and z-(u+v) designatethe average number of moles of the respective difunctional X, Y and Zunits which are present for every two moles of total monofunctionalunits (M_(o)) as shown, and that the values of y and z correspond to thetotal number of Q and E groups, respectively, contained in the polymer.Further, when t+w and u+v are zero, y and z also correspond to therespective total number of difunctional Y and Z units contained in thepolymer, as expressed on the normalized basis of two moles of M_(o).

In accordance with another aspect of the present invention, there isprovided a process for producing flexible polyurethane foam whichcomprises reacting and foaming a reaction mixture containing (a) apolyether polyol reactant containing an average of at least two hydroxylgroups per molecule; (b) a polyisocyanate reactant containing at leasttwo isocyanato groups per molecule; (c) a blowing agent; (d) a catalystcomprising a tertiary-amine; and (e) a foam stabilizing componentcomprising the cyanoalkoxyalkyl- and/or thecyanoalkoxyalkoxy-substituted organosiloxane-polyoxyalkylene polymers ofthe present invention. In addition to their efficacy as stabilizers ofpolyether-based urethane foams, it has been found that theorganosilicone polymers of this invention possess the furtheradvantageous property of allowing for the formation of flame-retardedfoams of reduced combustibility and acceptable overall quality. Inaccordance with this aspect of the present invention, flame-retardedflexible polyether-based urethane foams are provided by reacting andfoaming reaction mixtures which additionally include a flame-retardingagent.

In providing polyurethane foam as described herein, thecyano-substituted organosiloxane-polyoxyalkylene polymers can beintroduced to the foam-producing reaction mixtures either as such, indiluted form, in combination with other organosilicone polymers, orpreblended with one or more of the polyether polyol reactant, blowingagent, amine catalyst and, when used, the flame-retarding agent.

The present invention also relates to various methods for thepreparation of the novel organosiloxanepolyoxyalkylene polymersdescribed herein. One such method comprises the reation of: (1)polyoxyalkylene reactants which at one end are eitherhydroxyl-terminated or end-blocked by an olefinically unsaturated group,with (2) cyano-substituted polyalkylsiloxane hydrides having the averagecomposition expressed by the following Formula II, ##STR2## wherein: Z°is the difunctional hydro-alkylsiloxy unit, (H)(R)SiO_(2/2) ; X is (R)₂SiO_(2/2) ; Y is (Q)(R)SiO_(2/2) in which Q is the aforesaid --(O)_(q)--R'OR"--CN grouping; and, as defined with respect to Formula I, x hasan average value from about 10 to about 200, y has an average value fromabout 2 to about 100, z has an average value from about 2 to about 30,t, u, v, w, t+u and v+w are zero or one, and t+w and u+v are zero, oneor two, the respective values of these various parameters correspondingto those of any given polymer composition encompassed by Formula I.Another method for producing copolymers of the invention comprises theoverall reaction of: reactant (1) above; (2) olefinically unsaturatedcyanoalkyl ethers or hydroxyalkyl cyanoalkyl ethers; and (3)polyalkylsiloxane hydrides having the average composition,

    [M][X].sub.x [Z°].sub.y+z [M)                       (III)

wherein: M, X, Z° and x are as previously defined, and the value of y+zcorresponds to that of the sum y+z of any given copolymer compositionwithin Formula I.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

The functionality of the respective types of structural unitsencompassed by M_(o), X, Y and Z of the polymers of this inventiondenotes the number of oxygen atoms to which the silicon atom (Si) of anyparticular unit is bonded. Since each oxygen atom is shared by a siliconatom (Si') of another unit, functionality also denotes the number oflinkages by which the particular unit can be bonded to another portionof the polymer through --Si--O--Si'-- bonds. Accordingly, in expressingthe individual formulas of the respective units of the polymers of thisinvention, fractional subscripts are used in which the value of thenumerator defines functionality (i.e., the number of oxygen atomsassociated with the silicon atom of the particular unit), and thedenominator, which in each instance is 2, denotes that each oxygen atomis shared with another silicon atom. In view of their monofunctionality,the M_(o) units are chain-terminating or end-blocking units and therespective oxygen atoms thereof are shared with silicon of one otherunit which can be X, Y or Z. On the other hand, X, Y and Z aredifunctional and thus the respective two oxygen atoms associated witheach silicon atom thereof are shared with respective silicon atoms ofother units. Thus, the reoccurring difunctional units may be distributedin the polymer randomly, alternately, as sub-blocks of repeating unitsof the same type, or in any combination of such arrangements. Further,the polymers of the invention comprise mixtures of polymer species whichdiffer in molecular weight, total polyoxyalkylene and siloxane contents,and in the type, arrangement and relative proportions of units.Therefore, as expressed herein, the parameters employed to denote thesevariables are average values and are based on the relative proportionsof reactants from which the various units are derived. It is to befurther understood that, consistent with convention in the art to whichthe present invention pertains, as expressed herein the formulas of thepolymers indicate their overall average empirical composition ratherthan any particular ordered arrangement of units or molecular weight ofany particular polymer species. With this understanding, the averagecomposition of the respective types of polymers encompassed by Formula Iabove may be expressed by the following formulae wherein the varioussiloxy units are shown in chemically combined form: ##STR3## wherein: R,Q, E, x, y and z are as above defined.

The silicon-bonded R groups are alkyls having from one to ten carbonatoms including linear and branched alkyls. Illustrative of suitablegroups encompassed by R are: methyl, ethyl, n-propyl, isopropyl,n-butyl, t-butyl, pentyl, hexyl, octyl and decyl. Of the various groupsrepresented by R, the lower alkyls (that is, those having from one tofour carbon atoms) are preferred of which methyl is especially suitable.It is to be understood that the R groups may be the same throughout thepolymer or they may differ as between or within units without departingfrom the scope of this invention. For example, when the endblockingmonofunctional units are M, that is, R₃ SiO_(1/2-), they may betrimethylsiloxy units and the difunctional X units, R₂ SiO_(2/2), may bediethylsiloxy and/or methylethylsiloxy units.

In the Q grouping of the Y and M" units, that is, in --(O)_(q)R'OR"--CN, R' and R" are bivalent alkylene radicals of the series,--C_(c) H_(2c) -- and --C_(d) H_(2d) -- respectively, where c is aninteger having a value from 3 to 8 (--R'--) and d is an integer having avalue from 2 to 4 (--R"--). Illustrative of suitable groups encompassedby --R"-- are ethylene (--CH₂ CH₂ --); trimethylene (--CH₂ CH₂ CH₂ --);propylene [--CH₂ CH(CH₃)--]; and tetramethylene [--(CH₂)₄ --].Illustrative of suitable groups encompassed by R' are: trimethylene,propylene, tetramethylene, sec-butylene, hexylene and octylene. Thepreferred R' groups have from three to four carbon atoms, and may be thesame as or different from R'. It is to be understood that the polymermay contain any combination of cyanoalkoxyalkyl (NC--R"O-- R'--) and/orcyanoalkoxyalkoxy (NC--R"O--R'O--) groups encompassed by Q. For example,the Y units of any particular polymer composition may be one or more ofthe following: 3-(2-cyanoethoxy)propyl methylsiloxy;3-(3-cyanopropoxy)propyl methylsiloxy; 3-(2-cyanoethoxy)propoxymethylsiloxy; 3-(2-cyanoethoxy)propyl ethylsiloxy;3-(2-cyanoethoxy)-2-methylpropyl methylsiloxy; 8-(2-cyanoethoxy)octylmethylsiloxy; 3-(2-cyano-2-methylethoxy)propyl methylsiloxy;3-(2-cyano-2-ethylethoxy)propyl methylsiloxy; and the like. Further,when the polymers of the invention contain Q-modified monofunctionalunits (M"), such units may be 3-(2-cyanoethoxy)propyl dimethylsiloxy;3-(2-cyanoethoxy)propoxy dimethylsiloxy; 3-(2-cyanoethoxy)propyldiethylsiloxy; 3-(2-cyanoethoxy)propyl methylethylsiloxy; and the like.

The average composition of the preferred polyoxyalkylene blocks (E) ofthe Z and M' units is, --(R)°_(p) --(OC_(a) H_(2a))_(b) --OG, wherein: pis zero or one; --R°--comprises a bivalent alkylene group a carbon atomof which is bonded to silicon; a has a value from 2 to 4 provided fromabout 20 to about 65 weight percent of the oxyalkylene units of thepolyoxyalkylene chain, --(C_(a) H_(2a) O)_(b) --, is constituted ofoxyethylene units; b has an average value such that the averagemolecular weight of the polyoxyalkylene chain is from about 1000 toabout 6000; and G is an organic cap. The remainder of thepolyoxyalkylene chain is usually formed of oxypropylene, oxybutylene ora combination of such units, although preferably the remainder isoxypropylene. It is to be understood that the oxyethylene and otheroxyalkylene units can be randomly distributed throughout thepolyoxyalkylene chain or they can be grouped in respective sub-blocks,provided the total average content of --(C₂ H₄ O)-- in the chain iswithin the aforesaid range. Most preferably, the polyoxyalkylene blockshave the formula, GO(C₃ H₆ O)_(m) (C₂ H₄ O)_(n) -- wherein m has anaverage value of from about 6 to about 82 and n has an average valuefrom about 4.5 to about 90, provided the average molecular weight of thechain, --(C₃ H₆ O)_(m) (C₂ H₄ O)_(n) --, is within the aforesaid rangeof 1000 to 6000, and from about 20 to about 65 weight per cent of thechain is constituted of oxyethylene units.

When present, the linking group (--R°--) between silicon and thatportion of the polyoxyalkylene block shown as --(OC_(a) H_(2a))_(b) OG,is a bivalent alkylene group, an alkylene-C(O)-- group or an--alkylene--NH--C(O)--0 group wherein the free valence of alkylene ofthe latter two groups is bonded to silicon. In these linking groups,alkylene has the more specific formula, --C_(e) H_(2e) --, where e has avalue from 2 to 6 and is usually no more than four. Illustrative ofsuitable groups encompassed by R° are: ethylene, trimethylene,propylene, tetramethylene, hexamethylene; corresponding --C_(e) H_(2e)--C(O)-- groups which together with oxygen of the polyoxyalkylene chainform an ester linkage; and corresponding --C_(e) H_(2e) --NH--C(O)--groups which in combination with oxygen of the polyoxyalkylene chainform carbamate linkages.

As further indicated by the formula of the polyoxyalkylene blocks (E) ofthe Z and M' units, the poly(oxyalkylene) chain is terminated by theorganic group, GO--, wherein G is a monovalent organic capping group.Illustrative of the organic caps encompassed by G are such groups as:R°°--, R°°NHC(O)--, and R°°C(O)--, wherein R°°is a monovalenthydrocarbon radical having from 1 to 12 carbon atoms, and is usuallyfree of aliphatic unsaturation. The groups (GO--) which endblock thepolyoxyalkylene chains are, therefore, corresponding R°°O--, R°°NHC(O)--and R°°C(O)O-- monovalent organic radicals. In the aforesaid capping (G)and terminal (GO--) groups, R°° can be any of the following: an alkylgroup including linear and branched chain alkyl groups having theformula, C_(f) H_(2f+1) --, wherein f is an integer from 1 to 12, suchas, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, octyl anddodecyl groups; a cycloaliphatic radical including monocyclic andbicyclic groups such as, for example, cyclopentyl, cyclohexyl andbicyclo[2.2.1]heptyl groups; an aromatically unsaturated group includingaryl, alkaryl and aralkyl radicals such as, for example, phenyl,naphthyl, xylyl, tolyl, cumenyl, mesityl, t-butylphenyl, benzyl,beta-phenylethyl and 2-phenylpropyl groups; alkyl- and aryl-substitutedcycloaliphatic radicals such as, for example, methylcyclopentyl andphenylcyclohexyl radicals; and the like. It is evident, therefore, thatthe terminal group (GO--) of the polyoxyalkylene chain can becorresponding alkoxy, aryloxy, aralkoxy, alkaryloxy, cycloalkoxy,acylox, aryl--C(O)O--, alkyl carbamate and aryl carbamate groups.

The generally preferred R°° groups are phenyl, lower alkyl radicals, thelower alkyl-substituted aryl groups and the aryl-substituted lower alkylgroups, wherein the term "lower alkyl" denotes C₁ -C₄ alkyl radicals.Therefore, illustrative of the preferred capping groups represented by Gare: methyl, ethyl, propyl, butyl, phenyl, benzyl, phenylethyl (C₆ H₅--C₂ H₄ --), acetyl, benzoyl, methylcarbamyl [CH₃ NHC(O)--],ethylcarbamyl [C₂ H₅ NHC(O)-], propyl- and butyl-carbamyl groups,phenylcarbamyl [C₆ H₅ NHC(O)-], tolylcarbamyl [(CH₃)C₆ H₄ NHC(O)-],benzylcarbamyl [C₆ H₅ CH₂ NHC(O)--], and the like.

It is to be understood that the terminal organic radical (GO--) of therespective polyoxyalkylene blocks of the polymers of the presentinvention may be the same throughout the polymer or may differ. Forexample, the polymer compositions of this invention can containpolyether blocks in which the terminal group (GO--) is methoxy, andother polyether groups in which GO-- is a hydrocarbylcarbamate groupsuch as methylcarbamate, CH₃ NHC(O)O--, or benzyloxy (C₆ H₅ CH₂ O--).

When used to stabilize polyether polyol-derived flexible foam, anaverage of from about 55 to about 85 weight percent of thecyano-substituted organosiloxane-polyoxyalkylene polymers of theinvention is constituted of polyoxyalkylene blocks (E) which portion ofthe polymers is also referred to herein as the total polyether content.Correspondingly, the total siloxane content of the polymers is fromabout 45 to about 15 weight percent, and represents the sum of thecombined weight of the units encompassed by the M_(o), X, Y and Z unitsless the total weight of the polyoxyalkylene blocks (E).

In the polymers described herein, the alkyls (R) are of course bonded tosilicon by silicon-to-carbon bonds. On the other hand, the respectivecyano-bearing ether groups (Q) and polyoxyalkylene blocks (E) shown inFormulas I and IV-VII, may be bonded to silicon throughsilicon-to-carbon or silicon-to-oxygen bonds, as expressed by thefollowing general formulas: ##STR4## wherein, as previously defined, qand p may independently be zero or one. Thus, the cyano-substitutedorganosiloxanepolyoxyalkylene polymers of the invention may be: (1) nonhydrolyzable with respect to both the polyoxyalkylene blocks andcyano-substituted ether groups (when p is one and q is zero); (2)hydrolyzable with respect to both the polyoxyalkylene blocks andcyano-substituted ether groups (when p is zero and q is one); (3)hydrolyzable with respect to the polyoxyalkylene blocks and nonhydrolyzable with respect to the cyano-substituted ether groups (whenboth p and q are zero); and (4) non hydrolyzable with respect to thepolyoxyalkylene blocks and hydrolyzable with respect to thecyano-substituted ether groups (when both p and q are one).

From the standpoint of use as stabilizers of flame-retardedpolyether-based urethane foam, preferred polymers of the invention arethose having the average compositions: ##STR5## wherein: Me representsmethyl (--CH₃); x has an average value from about 10 to about 200, y hasan average value from about 2 to about 100, z has an average value fromabout 2 to about 30, the average values of x, y and z in any givenpolymer composition being such that the siloxane and polyether contentsof the polymer are within the aforesaid ranges; G represents an R°°--,R°°C(O)-- or R°°NHC(O)-- group, where R°°-- is lower alkyl,ar(lower)alkyl, or phenyl; and m and n are positive numbers such thatthe average oxyethylene content of the oxyalkylene chain ranges fromabout 20 to about 65 weight per cent and the average molecular weight ofthe chain is from about 1000 to about 6000.

From the standpoint of relative proportions of the X, Y and Z units, thepreferred polymers of the invention for use as stabilizers of polyetherurethane foam, are those wherein x has an average value from about 20 toabout 100, y has an average value from about 3 to about 30, and z has anaverage value from about 2 to about 10.

The polymers of the invention are prepared by any one of a number ofreactions, the particular method employed depending primarily on whetherthe polyoxyalkylene blocks (E) are linked to silicon through an Si--C orSi--O--C linkage and whether the bond between silicon and thecyano-substituted ether groups (Q) is Si--C (that is, when Q is--R'OR"--CN) or Si--O--C (that is, when Q is --O--R'OR"--CN).

One method for providing polymer compositions of the invention in whichthe polyoxyalkylene blocks of the Z and/or M' units are linked tosilicon through Si--C bonds comprises the platinum-catalyzed addition ofmonoolefinic polyoxyalkylene ethers to the Q-substitutedpolyalkylsiloxane Si-H fluids encompassed by Formula II hereinabove. Thehydrosilation reaction is referred to herein as Method A and isillustrated by the following equation wherein the said Si--H reactant isexpressed by Formula II-A, as shown: . ##STR6## wherein as previouslydefined herein: Q is the cyano-bearing ether group, --(O)_(q)--R'OR"--CN; R is alkyl; G is an organic cap; --(OC_(a) H_(2a))--is apoly(oxyalkylene) chain constituted of from about 20 to about 65 weightpercent oxyethylene; e has a value from 2 to 6; t, u, v, w, t+u and v+whave respective values of zero or one; t+w and u+v have respectivevalues of zero, one or two; x has an average value from about 10 toabout 200; y has an average value from about 2 to about 100; and Z hasan average value from about 2 to about 30.

Preferably, the monoolefinic group, --C_(e) H_(2e--1), of the polyetherreactant employed in Method A is vinyl, allyl or methallyl, the allylend-blocked reactants being especially suitable. One method forpreparing such polyether reactants comprises starting alkylene oxidepolymerization with an alkenol having at least three carbon atoms suchas allyl alcohol to provide HO(C_(a) H_(2a) O)_(b) C_(e) H_(2e-1)(wherein e has a value of at least 3), followed by capping of theterminal hydroxyl group with the aforesaid organic radical G--, such asmethyl, phenyl, benzyl, acetyl, methylcarbamyl and like capping groups.Further details concerning the method of preparation of such polyetherreactants are as described in British Patent Specifications 1,220,471and 1,220,472. Alternatively, the polyether reactants can be prepared bystarting the alkylene oxide polymerization with an alkanol such asmethanol or butanol, an aralkyl alcohol such as benzyl alcohol, phenoland the like, followed by capping of the terminal hydroxyl group of thereaction product with the monoolefinic group such as vinyl, allyl,methallyl and the like. Of these monoolefinically unsaturated polyetherreactants, allyl alcohol-started polyoxyalkylene ethers are especiallysuitable. It is to be understood that the polyoxyalkylene chain,--(C_(a) H_(2a) O)_(b) --, of the polyether reactants is composed offrom about 20 to about 65 weight percent of oxyethylene units, --(C₂ H₄O)--, the remaining oxyalkylene units being oxypropylene and/oroxybutylene, as described hereinabove with reference to the nature ofthe polyoxyalkylene blocks (E) of the copolymeric product. The differenttypes of oxyalkylene units can be randomly distributed throughout thechain such as when a mixture of alkylene oxides is polymerized, or theycan be arranged as sub-blocks such as when the respective alkyleneoxides are polymerized sequentially.

The polymers of this invention wherein polyoxyalkylene blocks are joinedto silicon through an Si--O--C bond (that is, the compositionsencompassed by Formulas IV-A through VII-A above wherein p is zero), areprovided by the catalyzed condensation of silicon-bonded hydrogen of theQ-substituted polyalkylsiloxane hydride fluids with hydrogen of the --OHgroup of hydroxyl-terminated polyether reactants. This method isreferred to herein as Method B and is illustrated by the reaction of thefollowing equation 2 in which the said hydride reactant has the averagecomposition expressed by Formula II-A shown in above equation 1.##STR7## wherein: Q, R, G, --(OC_(a) H_(2a))_(b) --, t through z, t+u,v+w, t+w and u+v have the aforesaid significance such as is summarizedwith specific reference to equation 1.

From equations 1 and 2 it is evident that when t, u, v and w are zero,the respective polymer products are endblocked by M units [(R)₃SiO_(1/2) ] and the polymer products are of the type encompassed byFormula IV, as illustrated by the following equations 1a and 2a:##STR8## wherein R, Q, G, x, y, z, a and b are as previously defined.

It is also evident from equations 1 and 2 that: (1) when t and w areboth one and thus u and v are zero, the end-blocking units are M"[(Q)(R).sub. 2 SiO_(1/2) ] and the polymer products are of the typeencompassed by Formula V; (2) when t and w are both zero and u and v areboth one, the endblocking units are M' [(E)(R).sub. 2 SiO_(1/2) ] andthe copolymers are within the scope of Formula VI; (3) when t and v areboth one and thus u and w are zero, the copolymers are endblocked bydifferent monofunctional units (M' and M") as defined by Formula VII;and (4) when the sum t+u+v+w is one, the copolymers also have differentendblocking units, that is, a combination of M and M' or M".

When the cyano-substituted ether group [--(O)_(q) --R'OR"--CN, alsoexpressed herein as --(O)_(q) C_(c) H_(2c) OC_(d) H_(2d) --CN] of the Yand/or M" units of the polymers of this invention is bonded to siliconby an Si--C bond, that is, when q is zero, the polymers may also beprepared by the method which comprises the platinum-catalyzed additionof polyalkylsiloxane hydrides or polyether-substituted polyalkylsiloxanehydrides to monoolefinic cyanoalkyl ethers having the formula, C_(c)H_(2c-1) OC_(d) H_(2d) CN, where c, as previously defined has a valuefrom 3 to 8, and d has a value from 2 to 4. For example, in accordancewith one embodiment of this method, referred to herein as Method C, thehydrosilation of the monoolefinic cyanoalkyl ether is carried outconcurrently with hydrosilation of monoolefinically endblocked polyetherreactants as illustrated by the following equation 3 in which the Si--Hreactant is that encompassed by above Formula III. ##STR9## It is to beunderstood that the reaction of equation 3 may also be carried out byfirst hydrosilating z moles of the polyether reactant to provide anintermediate having the average composition, ##STR10## which is thenreacted with y moles of the monoolefinic cyanoalkyl ether to provide theproduct shown in equation 3.

In accordance with still another embodiment of Method C, thepolyalkylsiloxane hydride fluid shown in equation 3 is reacted initiallywith y moles of the monoolefinic cyanoalkyl ether followed by reactionof the intermediate cyanoalkoxyalkyl-modified polyalkylsiloxane hydridewith z moles of either the monoolefinically unsaturated polyetherreactant shown in equation 1 or the hydroxylterminated polyetherreactant shown in equation 2. This sequence of reactions is illustratedby equations 3a-3c wherein allyl 2-cyanoethyl ether is shown as thecyano-bearing reactant: ##STR11## wherein R, G, a, b, e, x, y and z areas previously defined. When R is methyl and the polyether reactants areGO(C₂ H₄ O)_(n) (C₃ H₆ O)_(m) CH₂ CH=CH₂ and GO(C₂ H₄ O)_(n) (C₃ H₆O)_(m) --H, the polymer products of equations 3b and 3c have the averagecompositions shown hereinabove by Formulas VIII and IX, respectively.

When the cyano-substituted ether groups, --(O)_(q) --R'OR"--CN, of thesiloxane-polyoxyalkylene block copolymers of this invention arecyanoalkoxyalkoxy groups, that is, when q is one, the polymers areprepared by the method which comprises hydrogen condensation of Si--Hand HO-C groups derived respectively from polyalkylsiloxane hydrides andhydroxyalkyl cyanoalkyl ethers having the formula, HO--C_(c) H_(2c)--O--C_(d) H_(2d) --CN wherein the value of c, as previously defined, isfrom 3 to 8, and the value of d is from 2 to 4. In accordance with oneembodiment of this method, referred to herein as Method D, thecondensation reaction is carried out simultaneously with hydrogencondensation of Si-H of the polyalkylsiloxane hydride and HO-C ofhydroxyl-terminated polyether reactants, as shown by the followingequation 4 in which the Si-H reactant is also that encompassed byFormula III. ##STR12## wherein R, G, a, b, c, d, x, y and z have theabove defined significance. It is to be understood that the reaction ofequation 4 may also be carried out by first reacting z moles of thepolyether reactant with the polyalkylsiloxane hydride to provide anintermediate having the average structure: ##STR13## which is thenreacted with y moles of the hydroxyalkyl cyanoalkyl ether to provide thepolymer product shown in equation 4. In accordance with anotherembodiment of Method D, the polyalkylsiloxane hydride fluid is partiallyreacted initially with y moles of the cyano-bearing ether reactantfollowed by reaction of the intermediate cyanoalkoxyalkoxy-modified Si-Hfluid with z moles of either the monoolefinically unsaturated polyetherreactant shown in equation 1 or the hydroxyl-terminated polyetherreactant shown in equation 2. This sequence of reactions is illustratedby the following equations 4a-4c: ##STR14## wherein R, G, a, b, c, d, e,x, y and z are as previously defined. When R is methyl, and thecyano-bearing ether reactant is 3-hydroxypropyl 2-cyanoethyl ether (andthus c is three and d is two), and the polyether reactants are GO(C₃ H₆O)_(m) (C₂ H₄ O)_(n) CH₂ CH=CH₂ and GO(C₃ H₆ O)_(m) (C₂ H₄ O)_(n) --H,the polymer products of equations 4b and 4c have the compositions shownhereinabove by Formulas X and XI, respectively.

The hydrosilation reactions illustrated by equations 1, 1a, 3, 3a, 3band 4b, which overall comprise the addition of Si--H to the respectivemonoolefinic groups of the polyether and cyano-substituted monoetherreactants, are effected in the presence of a platinum catalyst.Particularly effective is platinum in the form of chloroplatinic aciddissolved, if desired, in a solvent such as tetrahydrofuran, ethanol,butanol or mixed solvents such as ethanol-ethylene glycol dimethylether. It is to be understood, however, that other platinum derivativesknown to the art as hydrosilation catalysts may also be used such asthose prepared in accordance with the method of U.S. Pat. No. 3,220,972.The platinum is present in a catalytic amount such as, for example, fromabout 5 to about 400 parts by weight per million (p.p.m.) parts of thecombined weight of the silicon-containing and organic reactants. Themore usual platinum concentration is from about 25 to about 300 p.p.m.Suitable reaction temperatures range from about room temperature (20°C.) to about 200° C., and are more usually from about 60° C. to about160° C.

The condensation reactions illustrated by equations 2, 2a, 3c, 4, 4a and4c which overall comprise the reaction of silanic hydrogen (Si--H) andhydrogen of the --OH groups of the hydroxyl-terminated polyetherreactant and the hydroxyalkyl cyanoalkyl ether reactant, are promoted bya variety of catalysts such as organic derivatives of tin, platinum andother transition metals. Especially suitable are organic derivatives oftin such as tin carboxylates which are typically illustrated by stannousoctoate, stannous oleate, stannous laurate and dibutyltin dilaurate.These catalysts are employed in amounts from about 0.1 to about 5, andusually no more than about 2, weight percent, based on the total weightof the reactants. The Si--H/HO--C condensation reactions are effected attemperatures from about 60° C. to about 150° C., and more usually fromabout 80° C. to about 120° C.

The various reactions of equations 1 through 4c are usually carried outemploying the organic reactants (that is, the polyether andcyano-substituted ether) in amounts at least sufficient to react with apredetermined proportion of the silicon-bonded hydrogen of the Si-Hreactant. From the standpoint of more effective and more completereaction of silanic hydrogen, the organic reactants are usually employedin excess of stoichiometric requirements. In those reactions (equations1, 1a, 2, 2a, 3b, 3c, 4b and 4c) wherein the Si-H groups are to becompletely reacted with only one of the organic reactants to form thedesired final polymer, the organic reactant may be employed in amountsof up to a 100 or more mole percent excess. In the case of the polyetherreactant, however, usually no more than about a 50 mole percent excessis used. On the other hand, when the Si-H reactant is either partiallyreacted initially with one of the organic reactants as shown, forexample, by equations 3a and 4a, or is reacted with the polyether andcyano-substituted ether reactants concurrently as shown by equations 3and 4, the organic reactants are employed in an amount just sufficientto satisfy the predetermined stoichiometric requirements of the desiredreaction or only a small excess such as up to about 50 (e.g., 20 to 30)mole percent is used. With respect to the hydrosilation reactions ofequations 3 and 3a it is usually desirable to employ the monoolefiniccyanoalkyl ether in excess of the desired stoichiometric reaction inview of the tendency of such reactants to undergo isomerization andreduction. For example, the allyl 2-cyanoethyl ether reactant shown inequation 3a can undergo isomerization and reduction in the presence ofSi-H and platinum catalyst to form the respective by-products, CH₃CH═CHOCH₂ CH₂ CN and CH₃ CH₂ CH₂ OCH₂ CH₂ CN.

The hydrosilation and condensation reactions may be conducted in theabsence or presence of a solvent. Illustrative solvents are any of thefollowing employed individually or in combination with one another: thenormally liquid aromatic hydrocarbons such as benzene, toluene andxylene; alcohols such as n-propanol and isopropanol; ethers; etheralcohols; and other such non polar or polar solvents. Upon completion ofthe respective hydrosilation and condensation reactions, any unreactedmonoolefinic cyanoalkyl ether (including by-products derived therefrom)or hydroxyalkyl cyanoalkyl ether, or any organic solvent employed in thepolymer preparation, may be removed by conventional separationtechniques to obtain the final product comprising the polymercompositions of the invention. It is to be understood, however, thatsome portion or all of the solvent and excess reactants includingby-products thereof and the polyether reactant may remain in the productand that such diluted polymer compositions are within the scope and maybe used in accordance with the teachings of this invention. In thehydrosilation reactions, the removal or neutralization of thechloroplatinic acid catalyst is usually desirable for long range productstability. Neutralization is readily effected by adding sodiumbicarbonate to the reaction mixture followed by filtration of theresultant slurry to remove the neutralizing agent and platinum residues.

The Q-modified polyalkylsiloxane hydrides encompassed by Formulas II andII-A and employed in the reactions of equations 1, 1a, 2, 2a, 3b, 3c, 4band 4c, are in turn provided by any one of a number of methods. Overall,the methods employed in providing such cyano-substituted Si-Hcompositions comprise the use of various combinations of the precursorreactants described below as the source of the indicated siloxy units orQ groups.

a. Hexaalkyldisiloxanes, R₃ SiOSiR₃, when the endblocking units are R₃SiO_(1/2), that is, when t, u, v and w of Formulas II and II-A are zero.

b. Di[cyanoalkoxyalkyl]tetraalkyldisiloxanes, (NC-R"OR') (R)₂ SiOSi(R)₂(R'OR"-CN), when the endblocking units are (NC-R"OR')(R)₂ SiO_(1/2),that is, when t and w of Formulas II and II-A are both one. Suchreactants in turn are prepared by hydrolysis of (NC-R"OR')(R)₂ SiX°where X° is chlorine or bromine, employing about one mole of water forevery two moles of halide.

c. Dihydrogentetraalkyldisiloxanes, (H)(R)₂ SiOSi(R)₂ (H), when theendblocking units are (H)(R)₂ SiO_(1/2), that is, when u and v ofFormulas II and II-A are both one.

d. Cyclic dialkylsiloxane polymers, [R₂ SiO[_(h), where h usually has anaverage value of from about 3 to about 6, as the source of thedifunctional dialkylsiloxy units (X), R₂ SiO_(2/2).

e. Trialkyl-endblocked dialkylsiloxane polymers, R₃ SiO(R₂ SiO)_(r)SiR₃, where r has an average value of at least two and is usually nomore than about 10, as the source of the endblocking units, R₃SiO_(1/2), and as a source of the dialkylsiloxy units (X), R₂ SiO_(2/2).

f. Cyanoalkoxyalkyl-alkylsiloxane polymers as the source of the##STR15## units encompassed by Y where, as previously defined, R' is thebivalent alkylene radical, --C_(c) H_(2c) --, c having a value from 3 to8 and R" is bivalent alkylene, --C_(d) H_(2d) --, d having a value from2 to 4. These polymers are formed by the hydrolysis ofcyanoalkoxyalkyldichlorosilanes, NC--R"OR'--Si(R)Cl₂, followed by thebasecatalyzed dehydration-cyclization of the hydrolyzate to form cyclicshaving the formula, [NC-R"OR'-Si(R)O]_(w), the average value of w being3 or more.

g. Cyanoalkoxyalkylheptaalkylcyclotetrasiloxanes,[(NC-R"OR')(R)SiO][(R)₂ SiO]₃, as the source of both the X units and the(NC-R"OR')(R)SiO_(2/2) units encompassed by Y. Such cyclics are in turnprovided by the platinum-catalyzed hydrosilation reaction betweenhydrogenheptaalkylcyclotetrasiloxanes, [(H)(R)SiO][(R)₂ SiO]₃, and themonoolefinic cyanoalkyl ethers defined hereinbelow as reactant (i).

h. Polymeric alkysiloxane hydride fluids having an Si--H contentsufficient to provide from about 200 to about 372 cubic centimeters ofhydrogen per gram, as the source of ##STR16## that is, the Z° units ofFormula II.

i. Monoolefinic cyanoalkyl ethers, C_(c) H_(2c--1) OC_(d) H_(2d) CN,wherein c is from 3 to 8 and d is from 2 to 4 as the source ofNC--R"OR'-- of the NC--R"OR'--Si(R)O_(2/2) units encompassed by Y,wherein R' and R" are more particularly shown as the bivalent alkyleneradicals, --C_(c) H_(2c) -- and --C_(d) H_(2d) --, respectively.

j. Hydroxyalkyl cyanoalkyl ethers, NC--R"OR'--OH, as the source of theNC--R"OR'--O -- groups of the NC--R"OR'O--Si(R)O_(2/2) units encompassedby Y, wherein R' and R" are also more particularly expressed as theabove defined bivalent alkylene radicals, --C_(c) H_(2c) -- and --C_(d)H_(2d) --, respectively.

From Formulas II and II-A it is evident that, when each of t, u, v and wis zero and Y has the unit formula, (NC--R"OR')(R)SiO_(2/2), thecyano-substituted Si--H fluids have the average composition encompassedby the following Formula II-B wherein R' and R" are expressed as --C_(c)H_(2c) -- and --C_(d) H_(2d) --, respectively; ##STR17## wherein: R, aspreviously defined, is alkyl having from one to ten carbon atoms and ispreferably lower alkyl; c has a value of 3 to 8; d has a value of 2 to4; x has an average value from about 10 to about 200; y has an averagevalue from about 2 to about 100; and z has an average value from about 2to about 30. The compositions encompassed by Formula II-B are suitablyemployed to provide copolymers of the invention as illustrated byequations 3b and 3c hereinabove.

One method for preparing the compositions encompassed by Formula II-Bcomprises equilibration of various combinations of reactanrts (a) and(d)-(h). Illustrative are the reactions of the following equations 5 and6 which comprise equilibration of reactants (a) or (e), (d), (f) and(h), and in which polymeric reactants (d), (f) and (h) are shown, forconvenience, simply as the siloxy units which they provide to theequilibrated reaction product. ##STR18## In the above equations 5 and 6and other equations hereinbelow, g represents the actual number of molesof the indicated reactant, and x', y' and z' represent the actual numberof moles (or mole-equivalents) of the indicated monomeric units providedby the polymeric source of such units. It is to be understood,therefore, that g, x', y' and z' can be any positive numbers dependingupon the scale on which the reactions are run, provided that whennormalized on the basis of g=1 (or two moles of monofunctional units),the average values of the mole ratios x':y':z' (equation 5) and [x'+(g ×r)]:sy':z' (equation 6) are 10-200:2-100:2-30, respectively, therebyproviding Si--H fluids wherein the ratio x:y:z has a correspondingaverage value of 10-200:2-100:2-30, as previously defined.

In addition to the reactions of equations 5 and 6, the Si--H fluidsencompassed by Formula II-B may also be prepared by the equilibration ofreactants (a), (g) and (h), as illustrated by the following equation 7.##STR19## It is evident that in the cyanoalkoxyalkyl-modifiedpolyalkylsiloxane hydrides produced by the reaction of equation 7, theratio of x:y will of course be 3:1, corresponding to the ratio of the Xand Y units present in reactant (g). The ratio of x:y may be adjusted toabove or below 3:1, as desired, by effecting the reaction of equation 7in the presence of reactant (d) as an additional source of the X units,thereby increasing the ratio above three, or by the employment of anappropriate proportion of reactant (f) as an additional source of the Yunits, (NC--R"OR')(R)SiO_(2/2), thereby decreasing the ratio to lessthan three.

With further reference to general Formulas II and II-A, it is evidentthat when t and w are both one and Q is cyanoalkoxyalkyl, the Si--Hfluids have the average composition depicted by the following FormulaII-C in which the cyanoalkoxyalkyl groups are expressed as NC--C_(d)H_(2d) --O--C_(c) H_(2c) --. ##STR20## wherein R, c, d, x, y and z areas previously defined such as is summarized with specific reference toFormula II-B. Such compositions are employed to provide thecyanoalkoxyalkyl-substituted polysiloxane-polyoxyalkylene copolymerswithin the scope of Formfula V-A (wherein q is zero) by application ofthe reactions of equations 1 and 2 above. The Si--H compositions definedby Formula II-C are in turn provided by effecting the equilibrationreactions of equations 5-7 in the presence of reactant (b) instead ofreactants (a) and/or (e), as illustrated by the following modificationof equation 5. ##STR21## When y of Formula II-C is two, it is evidentthat the cyanoalkoxyalkyl groups are present solely in the endblockingmonofunctional units (M") and that such compositions are provided byeffecting the reaction of equation 8 in the absence of the cyclic sourceof the Y units, that is, in the absence of reactant (f).

With further reference to general Formulas II and II-A, it is evidentthat when u and v are both one and Q is cyanoalkoxyalkyl, the Si-Hfluids have the average composition depicted by the following FormulaII-D in which the cyanoalkoxyalkyl groups are expressed as NC--C_(d)H_(2d) --O--C_(c) H_(2c) --. ##STR22## wherein R, c, d, x, y and z arealso as summarized with specific reference to Formula II-B. Suchcompositions are employed, for example, to provide thecyanoalkoxyanlkylsubstituted polysiloxane-polyoxyalkylene copolymerswithin the scope of Formfula VI-A by application of the reactions ofequations 1 and 2. The Si-H compositions defined by Formula II-D are inturn provided by effecting the equilibration reactions of equations 5-7in the presence of reactant (c) instead of reactants (a) and/or (e), asillustrated by the following modification of equation 5. ##STR23## Inthe copolymers encompassed by Formula VI-A in which z is two, the Si-Hreactants employed to provide such copolymers will contain no Z° units[(H)(R)SiO_(2/2) ] and are prepared by effecting the reaction ofequation 9 in the absence of reactant (h).

In providing the Si-H fluids by the one-step reactions of equations 5 to9, standard base-catalyzed equilibration reaction conditions are notsuitable in view of the base-sensitivity of the Si--H groups. Therefore,the equilibration reactions of equations 5 to 9 are promoted by acidcatalysts. Suitable catalysts for this purpose aretrifluoromethylsulfonic acid (CF₃ SO₃ H) and concentrated (93-98 weightpercent) sulfuric acid. The catalyst is usually employed in aconcentration of from about 0.1 to about four weight percent, based onthe total weight of reactants. The acid-catalyzed equilibrationreactions are usually carried out with vigorous mechanical stirring attemperatures within the range from about 20° C. to about 120° C. atleast until the reaction mixture becomes homogeneous. Effecting thereaction at temperatures from about 20° C. to about 50° C. usuallyprovides a satisfactory rate of reaction. After completion of thereaction, the reaction product is neutralized with base such as sodiumbicarbonate and filtered, sometimes adding a liquid hydrocarbon such asxylene or toluene or a filter aid to facilitate the filtration. When adiluent is used, it is conveniently separated from the reaction productby rotary vacuum evaporation.

In addition to the one-step reactions of equations 5 to 9, thecyanoalkoxyalkyl-polyalkylsiloxane hydrides encompassed by generalFormulas II and II-A may also be prepared in step-wise manner. Forexample, the overall reaction of equation 5 may be effected by thefollowing sequence of reactions: ##STR24## In view of the fact that theSi--H reactant is not used in the reaction of equation 5a, it may beeffected in the presence of conventional alkaline equilibrationcatalysts useful in the preparation of unmodified polyalkylsiloxanes.Illustrative of such alkaline catalysts are potassium silanolate, cesiumhydroxide and tetramethyl ammonium silanolate. Such promoters areusually employed in concentrations of from about 30 to about 50 p.p.m.,based on the total weight of reactants. The temperature at which thebase-catalyzed equilibration reaction of equation 5a is carried outdepends largely on the catalyst employed. Thus, when tetramethylammonium silanolate is used, suitable reaction temperatures are fromabout 75° C. to about 100° C., preferably from about 80° C. to about 90°C. The other alkaline catalysts usually require higher temperatures suchas from about 150° C. to about 200° C. The further reaction of theproduct of equation 5a to introduce the ##STR25## units, as shown byequation 5b, is carried out in the presence of an acid equilibrationcatalyst as described with spcific reference to the reactions ofequations 5 to 9.

A third route to the cyanoalkoxyalkyl-polyalkylsiloxane hydridesencompassed by Formula II-B comprises the use of the monoelefiniccyanoalkyl ethers described above as reactant (i), as the source of thecyanoalkoxyalkyl groups, as illustrated by the following sequence ofreactions wherein allyl 2-cyanoethyl ether is shown as the cyanobearingether reactant: ##STR26## The reaction of equation 10a is effected inthe presence of acid equilibration catalysts such astrifluoromethylsulfonic acid and sulfuric acid, at temperatures usuallyfrom about 20° C. to about 50° C. The reaction of equation 10b isplatinum-catalyzed and is effected under the conditions described withspecific reference to the hydrosilation reactions shown, for example, byequation 1. The reaction of equation 10c is acid-catalyzed and iscarried out under the conditions described with reference to equations 5to 9, employing an acid equilibration catalyst. Prior to the furtherreaction of the intermediate fluid provided by equation 10b, however, itis desirable to separate any unreacted allyl cyanoalkyl ether orisomerized derivatives thereof, in order to minimize any tendency ofsuch compounds to react with the acid catalyst employed in the reactionof equation 10c. It is to be understood that, instead of introducing the##STR27## units in two stages (equations 10a and 10c), such units may beintroduced during the reaction of equation 10a in a predetermined amountsufficient to provide the total desired amount (y'+z') followed bypartial reaction of the Si--H groups with y' moles of the monoolefiniccyanoalkyl ether reactant. This latter embodiment is illustrated by thehydrosilation reaction of equation 3a above.

With further reference to general Formulas II and II-A, it is evidentthat when t through w are zero and Q is cyanoalkoxyalcosy, the Si--Hfluids have the average composition depicted by the following FormulaII-E, ##STR28## wherein R, c, d, x, y and z are also as summarized withspecific reference to Formula II-B. Such Si--H fluids are prepared bymethods which comprise the condensation of silanic hydrogen and hydrogenof the HO-13 C groups of the hydroxyalkyl cyanoalkyl ethers, HO--C_(c)H_(2c) --O--C hd dH_(2d) --CN, described above as reactant (j), as thesource of the cyanoalkoxyalkoxy groups. One such method is asillustrated by the reaction of equation 4a, which as previouslydescribed herein, is usually promoted by catalysts comprising tin suchas stannous octoate. By way of specific illustration,cyanoethoxypropoxy-substituted polymethylsiloxane hydrides having theaverage composition: ##STR29## are provided by the reaction of thefollowing equation 11 employing 3-hydroxypropyl 2-cyanoethyl ether asthe source of the 3-(2-cyanoethoxy)propoxy groups: ##STR30## Thereaction of equation 11 is carried out in the presence of the metalcatalysts, preferably tin carboxylates such as stannous octoate, asdescribed, for example, with specific reference to the reaction ofequation 2.

The Si-H fluids having Formula II-E-1 are useful in providing thepolysiloxane-polyoxyalkylene block copolymers encompassed by Formulas Xand XI by the respective hydrosilation and hydrogen condensationreactions of equations 1 and 2 employing, as the polyether reactants,the above-described allyl endblocked and hydroxyl-terminatedpoly(oxyethylene-oxypropylene) ethers, GO(C₂ H₄ O)_(n) (C₃ H₆ O)_(m) CH₂CH═CH₂ and GO(C₂ H₄ O)_(n) (C₃ H₆ O)_(m) --H, respectively.

The cyanoalkoxyalkyl- and cyanoalkoxyalkoxy-substitutedpolyalkylsiloxane hydrides having the average composition expressed byFormula II (including Formulas II-A through II-E) are described andclaimed in our copending application Ser. No. 536,874, filedconcurrently herewith, entitled "Cyano-Ether PolyalkylsiloxaneHydrides," now U.S. Pat. No. 3,943,156, granted Mar. 9. 1976.

The cyanoalkoxyalkyl- and cyanoalkoxyalkoxy siloxane-polyoxyalkylenecopolymers encompassed by Formula I and the corresponding Si--H fluidsencompassed by Formula II, are normally liquid compositions and, aspreviously described, comprise mixtures of polymer species which differin molecular weight, polyether and siloxane contents and relative numberof monomeric units. It is to be understood that two or more blockcopolymers or two or more Si--H fluids having a particular averagecomposition encompassed by respective Formulas I and II may be admixedin suitable relative proportions to adjust the average values of x, yand z, as desired. For example, a block copolymer wherein y has anaverage value of about 45 may be admixed with about an equimolarproportion of another composition wherein y has an average value ofabout 15 to provide a copolymer wherein y has an average value of about30. It is also to be understood that a small percentage (on the average,usually about 15 mole percent or less) of the polyoxyalkylene blocks ofthe copolymers of the invention may comprise residual, uncappedhydroxylterminated groups introduced with the polyoxyalkylene etherreactants.

The novel cyanoalkoxyalkyl- and cyanoalkoxyalkoxy-substitutedsiloxane-polyoxyalkylene copolymers of this invention are effective asstabilizers of flexible polyether urethane foams and can, therefore, beused as such without the need for combination with other surfactants, orother type of organic additive. The polymers can be employed as a 100percent active stream, or they can be employed in dilute form as asolution in various types of organic liquids including non polar andpolar solvents. For example, the polymers may be diluted with non polarsolvents such as the normally liquid aliphatic and aromaticunsubstituted and halogen-substituted hydrocarbons such as heptane,xylene, toluene, chlorobenzene and the like. When used, the preferreddiluents are poly(oxyalkylene) compounds encompassed by the formula:

    DO(D'O).sub.t °D"

wherein:

D is hydrogen or a monovalent hydrocarbon group including alkyl (e.g.,methyl, ethyl, propyl and butyl), aryl (e.g., phenyl and tolyl) andaralkyl (e.g., benzyl) groups;

D' is a bivalent alkylene group (e.g., ethylene, propylene, trimethyleneand butylene);

D" is a monovalent hydrocarbon group such as defined for D; and

t° has an average value of at least two.

When D is hydrogen, it is preferred that such Do-- (that is, hydroxyl)groups constitute no more than about 5 weight percent of the solvent.Generally suitable solvents are alkylene oxide adducts of starters suchas water, mono-ols, diols and other polyols, of which the organicstarters are preferred. Such organic starters are typically illustratedby butanol, propylene glycol, glycerol and 1,2,6-hexanetriol. Preferredadducts of the organic starters are the mixed alkylene oxide adducts,particularly those containing a combination of oxyethylene andoxypropylene units. For example, one class of such organic solventswhich may be present in combination with the copolymers of thisinvention are mixed ethylene oxide-propylene oxide adducts of butanolhaving the general formula, HO(C₂ H₄ O)_(u)° (C₃ H₆ O)_(v) °C₄ H₉,wherein u° has an average value from about 8 to about 50, and v° has anaverage value from about 6 to about 40. Preferably, the values of u° andv° are such that the weight percent of oxyethylene units issubstantially the same as the weight percent of the oxypropylene units.

When used, the aforesaid diluents are usually present in the solutioncompositions of this invention in an amount from about one to about 60,and more usually from about 5 to about 45, weight percent, based on thetotal weight of the cyanoalkoxyalkyl- and/orcyanoalkoxyalkoxy-substituted siloxane-polyoxyalkylene copolymercontained in the solution. It is to be understood, however, that suchsolutions may have higher contents of diluent and that the extent ofdilution, if any, depends largely on the activity specifications of anygiven foam formulation.

The cyano-bearing organosilicone polymer surfactants of the presentinvention may also be used in combination with non ionic organicsurfactants such as adducts produced by reacting k moles of ethyleneoxide (wherein k has an average value from about 4 to about 40,inclusive of whole and fractional numbers) per mole of any of thefollowing hydrophobes: n-undecyl alcohol, myristyl alcohol, laurylalcohol, trimethyl nonanol, tridecyl alcohol, pentadecyl alcohol, cetylalcohol, nonylphenol, dodecylphenol, tetradecylphenol and the like.Especially useful are ethylene oxide adducts of nonylphenol having theaverage composition, C₉ H₁₉ --C₆ H₄ --(OC₂ H₄)_(h) OH, wherein h has anaverage value from about 9 up to about 20 or more, including whole andfractional numbers such as 9, 10.5, 13, 14.5 and 15. When used, such nonionic organic surfactants are used in amounts from about 2 to about 20weight percent, based on the total weight of the cyano-bearing blockcopolymer. It is to be understood that such additives may also bepresent as a component of the aforementioned solutions of the blockcopolymers.

Also included within the scope of this invention are compositionscomprising the cyano-substituted polysiloxane-poloxyalkylene copolymersdescribed herein in combination with other types of silicon-containingsurfactants in which he polyoxyalkylene content is constituted ofbetween about 20 and about 75 weight percent of oxyethylene units.Illustrative of such auxiliary surfactants are those in which thebackbone of the siloxane blocks is substituted only with silicon-bondedmethyl or other alkyl groups such as, for example, the block copolymersdescribed in Reissue Pat. No. 27,541. Other organosilicones which can beused in combination with the surfactants of this invention are thosewherein the siloxane backbone is substituted with a combination of alkyl(for example, methyl) and aralkyl groups (for example, phenylethyl) suchas the block copolymers described in U.S. Pat. Nos. 3,657,305 and3,686,254. Illustrative of further organosilicones with which thepolymers of this invention may be used in combination are those whereinthe polysiloxane block is substituted with methyl only and thepolysiloxane and polyoxyalkylene blocks are linked by an Si--O--Clinkage such as, for example, the compositions described in U.S. Pat.No. 2,834,748. Especially suitable as the additional copolymer arepolymethylsiloxane-poly(oxyethylene-oxypropylene) block copolymerswherein the said poly(oxyethylene-oxypropylene) blocks are composed ofan admixture of: (1) from about 50 to about 95 weight percent of lowmolecular weight Poly(oxyethylene-oxypropylene) copolymers having anaverage molecular weight from about 800 to about 3000 and wherein fromabout 20 to about 75 weight percent of the oxyalkylene groups areoxyethylene; and (2) from about 50 to about 5 weight percent of a highermolecular weight poly(oxyethylene-oxypropylene) copolymer having anaverage molecular weight from about 1600 to about 6000 and wherein fromabout 20 to about 75 weight percent of the oxyalkylene groups areoxyethylene; the said admixutre of (1) and (2) having an averagemolecular weight no higher than about 6000.

When used, the additional organosilicone polymer may be in combinationwith the cyano-bearing copolymers of this invention in an amount fromabout 1 to about 80 weight percent, and usually in a minor amount (thatis, less than 50 weight percent), based on the combined weight of thecyano-bearing copolymers of the invention and the additional copolymercontained in the admixtures thereof.

In addition to the cyanoalkoxyalkyl- and cyanoalkoxyalkoxy-substitutedpolysiloxane-polyoxyalkylene copolymers of the invention, the otheressential types of components and reactants employed in providingflexible polyurethane foams as described herein are polyether polyols,organic polyisocyanates, the catalyst system and blowing agent, and,when producing flame-retarded foam, the foam-producing reaction mixturealso contains a flame-retardant. The cyano-substituted foam-stabilizingcopolymers of the present invention are usually present in the finalfoam-producing reaction mixtures in an amount from about 0.1 to about 5parts by weight per 100 parts by weight of the polyether polyolreactant.

In producing the flexible polyurethane polymers of the presentinvention, one or more polyether polyols is employed for reaction withthe polyisocyanate reactant to provide the urethane linkage. Suchpolyols have an average of at least two, and usually not more than six,hydroxyl groups per molecule and include compounds which consist ofcarbon, hydrogen and oxygen and compounds which also contain phosphorus,halogen and/or nitrogen.

Among the suitable polyether polyols that can be employed are thepoly(oxyalkylene) polyols, that is, alkylene oxide adducts of water or apolyhydric organic compound as the initiator or starter. Forconvenience, this class of polyether polyols is referred to herein asPolyol I. Illustrative of suitable polyhydric organic initiators are anyone of the following which may be employed individually or incombination: ethylene glycol; diethylene glycol; propylene glycol;1,5-pentanediol; hexylene glycol; dipropylene glycol; triethyleneglycol; 1,2-cyclohexanediol; 3-cyclohexene-1,1-dimethanol and the3,4-dibromo-derivative thereof; glycerol; 1,2,6-hexanetriol;1,1,1-trimethylolethane; 1,1,1-trimethylolpropane; 3-(2-hydroxyethoxy)-and 3-(2-hydroxypropoxy)-1,2-propanediols;2,4-dimethyl-2-(2-hydroxyethoxy)methylpentanediol-1,5;1,1,1-tris[(2-hydroxyethoxy)methyl]ethane;1,1,1-tris[(2-hydroxypropoxy)methyl]propane; pentaerythritol; sorbitol;sucrose; alpha-methyl glucoside; other such polyhydric compoundsconsisting of carbon, hydrogen and oxygen and having usually not morethan about 15 carbon atoms per molecule; and lower alkylene oxideadducts of any of the aforesaid initiators such as propylene oxide orethylene oxide adducts having a relatively low average molecular weightup to about 800.

The above-described polyether polyols are normally liquid materials and,in general, are prepared in accordance with well known techniquescomprising the reaction of the polyhydric starter and an alkylene oxidein the presence of an oxyalkylation catalyst which is usually an alkalimetal hydroxide such as, in particular, potassium hydroxide. Theoxyalkylation of the polyhydric initiator is carried out at temperaturesranging from about 90° C. to about 150° C. and usually at an elevatedpressure up to about 200 p.s.i.g., employing a sufficient amount ofalkylene oxide and adequate reaction time to obtain a polyol of desiredmolecular weight which is conveniently followed during the course of thereaction by standard hydroxyl number determinations. As is well known tothis art, the hydroxyl numbers are determined by, and are defined as,the number of milligrams of potassium hydroxide required for thecomplete neutralization of the hydrolysis product of the fullyacetylated derivative prepared from 1 gram of polyol or mixture ofpolyols. The hydroxyl number is also defined by the following equationwhich indicates its relationship with the molecular weight andfunctionality of the polyol: ##EQU1## wherein OH = hydroxyl number ofthe polyol,

f = average functionality, that is, the average number of hydroxylgroups per molecule of polyol, and

M.w. = average molecular weight of the polyol.

The alkylene oxides usually employed in providing the polyether polyolreactants are the lower alkylene oxides, that is, compounds having from2 to 4 carbon atoms including ethylene oxide, propylene oxide, butyleneoxides (1,2- or 2,3-) and combinations thereof. When more than one typeof oxyalkylene unit is desired in the polyol product, the alkylene oxidereactants may be fed to the reaction system sequentially to providepolyoxyalkylene chains containing respective blocks of differentoxyalkylene units or they may be fed simultaneously to providesubstantially random distribution of units. Alternatively, thepolyoxyalkylene chains may consist essentially of one type ofoxyalkylene unit such as oxypropylene capped with oxyethylene units.

A second class of polyether polyols that are suitable for use inpreparing the flexible polyurethane foams of the present invention arepolymer/polyether polyols which, for convenience, are referred to hereinas Polyol II. Such reactants are produced by polymerizing one or moreethylenically unsaturated monomers dissolved or dispersed in a polyetherpolyol in the presence of a free radical catalyst. Suitable polyetherpolyols for producing such compositions include, for example, any of theabove-described polyols encompassed by the definition of Polyol I.Illustrative of suitable ethylenically unsaturated monomers are thoseencompassed by the general formula, ##STR31## where: R°°° is hydrogen,methyl or any of the halogens (i.e., fluorine, chlorine, bromine oriodine); and R°°°° is R°°°, cyano, phenyl, methyl-substituted phenyl, oralkenyl radicals having from 2 to 6 carbon atoms such as vinyl, allyland isopropenyl groups. Typical examples of such polymerizable monomersare the following which may be employed individually or in combination:ethylene, propylene, acrylonitrile, methacrylonitrile, vinyl chloride,vinylidene chloride, styrene, alpha-methylstyrene, and butadiene. Theseand other polymer/polyol compositions which are suitably employed eitherindividually or in combination with Polyol I are those described inBritish Pat. No. 1,063,222 and U.S. Pat. No. 3,383,351, the disclosuresof which are incorporated herein by reference thereto. Such compositionsare prepared by polymerizing the monomers in the polyol at a temperaturebetween about 40° C. and about 150° C. employing any freeradical-generating initiator including peroxides, persulfates,percarbonates, perborates, azo compounds such as, for example, hydrogenperoxide, dibenzoyl peroxide, benzoyl hydroperoxide, lauroyl peroxide,and azobis(isobutyronitrile). The polymer/polyether polyol product mayalso contain a small amount of unreacted polyether, monomer and freepolymer.

When used in the practice of this invention, the polymer/polyolcompositions usually contain from about 5 to about 50, and more usuallyfrom about 10 to about 40, weight percent of the ethylenicallyunsaturated monomer polymerized in the polyether polyol. Especiallysuitable polymer/polyols are those containing:

A. from about 10 to about 30 weight percent of a copolymer of (1)acrylonitrile or methacrylonitrile, and (2) styrene oralpha-methylstyrene, the said copolymer containing from about 50 to 75and from about 50 to 25 weight percent of (1) and (2), respectively; and

B. from about 90 to about 70 weight percent of the polyether polyol, andparticularly trifunctional polyols such as alkylene oxide adducts ofglycerol.

In preparing polyurethane foams in accordance with the presentinvention, it is to be understood that mixtures of any of the aforesaidpolyether polyols encompassed by Polyol I and Polyol II can be employedas reactants with the organic polyisocyanate. The particular polyetherpolyol or polyols employed depends upon the end-use of the polyurethanefoam. Usually diols provide soft foams. Firmer foams are obtained by theincorporation of polyether polyols having more than two hydroxyl groups,including triols, tetraols, pentols and hexols. When it is desired toproduce polyurethanes having comparatively high load-bearing propertiesand/or diecutability, polymer/polyether polyols of the aforesaid typeare used.

The hydroxyl number of the polyether polyol reactant including mixturesof polyols employed in the production of the flexible polyurethane foamsof this invention may vary over a relatively wide range such as fromabout 28 to about 150, and is usually no higher than about 80.

The polyisocyanates used in the manufacture of polyurethanes are knownto the art and any such reactants are suitably employed in producing theflexible polyether-based polyurethane foams of the present invention.Among such suitable polyisocyanates are those represented by the generalformula,

    Q'(NCO).sub.i

wherein: i has an average value of at least two and is usually no morethan six, and Q' represents an aliphatic, cycloaliphatic or aromaticradical which can be an unsubstituted hydrocarbyl group or a hydrocarbylgroup substituted, for example, with halogen or alkoxy. For example, Q'can be an alkylene, cycloalkylene, arylene, alkyl-substitutedcycloalkylene, alkarylene or aralkylene radical including correspondinghalogen- and alkoxy-substituted radicals. Typical examples of suitableorganic polyisocyanates for use in preparing the polyurethanes of thisinvention are any of the following including mixtures thereof:1,6-hexamethylene diisocyanate; 1,4-tetramethylene diisocyanate;1-methyl-2,4-diisocyanatocyclohexane; bis(4-isocyanatophenyl)methane;4-methoxy-1,4-phenylenediisocyanate; 4-chloro-1,3-phenylenediisocyanate;4-bromo-1,3-phenylenediisocyanate,5,6-dimethyl-1,3-phenylenediisocyanate; the isomeric tolylenediisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylenediisocyanate and mixtures thereof; crude tolylene diisocyanates;6-isopropyl-1,3-phenylenediisocyanate; durylene diisocyanate;triphenylmethane-4,4',4"-triisocyanate; and other organicpolyisocyanates known to the polyurethane art. Other suitablepolyisocyanate reactants are ethylphosphonic diisocyanate andphenylphosphonic diisocyanate. Of the aforesaid types ofpolyisocyanates, those containing aromatic nuclei are generallypreferred.

Also useful as the polyisocyanate reactant are polymeric isocyanateshaving units of the formula, ##STR32## wherein R''' is hydrogen and/orlower alkyl and j has an average value of at least 2.1. Preferably thelower alkyl radical is methyl and j has an average value of from 2.1 toabout 3.0. Particularly useful polyisocyanates of this type are thepolyphenylmethylene polyisocyanates produced by phosgenation of thepolyamine obtained by acid-catalyzed condensation of aniline withformaldehyde. Polyphenylmethylene polyisocyanates of this type areavailable commercially (e.g., NIAX Isocyanate AFPI), and are lowviscosity (50-500 centipoises at 25° C.) liquids having averageisocyanato functionalities in the range of about 2.25 to about 3.2 orhigher, depending upon the specific aniline-to-formaldehyde molar ratioused in the polyamine preparation.

Other useful polyisocyanates are combinations of diisocyanates withpolymeric isocyanates containing moe than two isocyanate groups permolecule. Illustrative of such combinations are: a mixture of2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and the aforesaidpolyphenylmethylene polyisocyanates and/or polymeric tolylenediisocyanates obtained as residues from the manufacture of thediisocyanates.

On a combined basis, the polyether polyol and organic polyisocyanateusually constitute the major proportion by weight of thepolyurethane-forming reaction mixture. In general, the polyisocyanateand polyether polyol reactants are employed in relative amounts suchthat the ratio of total --NCO equivalents to total active hydrogenequivalent (of the polyether polyol and any water, when used) is from0.8 to 1.5, preferably from 0.9 to 1.1, equivalents of --NCO perequivalent of active hydrogen. This ratio is known as the IsocyanateIndex and is often also expressed as a percent of the stoichiometricamount of polyisocyanate required to react with total active hydrogen.When expressed as a percent, the Isocyanate Index may be from 80 to 150,and is preferably within the range from about 90 to about 110.

The urethane-forming reaction is effected in the presence of a minoramount of a catalyst comprising an amine. This component of thepolyurethane-forming reaction mixture is usually a tertiary-amine.Suitable amine catalysts include one or more of the following:N-methylmorpholine; N-ethylmorpholine; N-octadecylmorpholine;triethylamine; tributylamine, trioctylamine;N,N,N',N'-tetramethylethylenediamine;N,N,N',N'-tetramethyl-1,3-butanediamine; triethanolamine;N,N-dimethylethanolamine; triisopropanolamine; N-methyldiethanolamine;hexadecyldimethylamine; N,N-dimethylbenzylamine; trimethylamine;N,N-dimethyl-2-(2-dimethylaminoethoxy)ethylamine, also known asbis(2-dimethylaminoethyl)ether; triethylenediamine (i.e.,1,4-diazabicyclo[2.2.2]octane); the formate and other salts oftriethylenediamine, oxyalkylene adducts of the amino groups of primaryand secondary amines and other such amine catalysts which are well knownin the art of polyurethane manufacture. Also useful are thebeta-tertiary amino amides and esters described in U.S. Pat. No.3,821,131, as exemplified by3-(N,N-dimethylamino)-N',N'-dimethylpropionamide. Also useful as theamine catalyst are the beta-tertiary-amino nitriles described incopending application Ser. No. 369,556, filed June 13, 1973, of W. R.Rosemund, M. R. Sandner and D. J. Trecker, (now U.S. Pat. No. 3,925,268)such as, in particular, 3-(N,N-dimethylamino)-propionitrile as such orin combination with other tertiary amines such asbis[2-(N,N-dimethylamino)ether. The amine catalyst may be introduced tothe polyurethane-producing reaction mixture as such or as a solution insuitable carrier solvents such as diethylene glycol, dipropylene glycol,and 2-methyl-2,4-pentanediol ("hexylene glycol").

The amine catalyst is present in the final urethane-producing reactionmixture in an amount of from about 0.05 to about 3 parts by weight ofactive catalyst (that is, the amine exclusive of other componentspresent in solutions thereof) per 100 parts by weight of the polyetherpolyol reactant.

In producing polyurethanes from polyether polyols usual practice is toinclude as a further component of the reaction mixture a minor amount ofcertain metal catalysts which are useful in promoting gellation of thefoaming mixture. Such supplementary catalysts are well known to the artof flexible polyether-based polyurethane foam manufacture. For example,useful metal catalysts include organic derivatives of tin, particularlytin compounds of carboxylic acids such as stannous octoate, stannousoleate, stannous acetate, stannous laurate, dibutyl tin dilaurate, andother such tin salts. Additional metal catalysts are organic derivativesof other polyvalent metals such as zinc and nickel (e.g., nickelacetylacetonate). In general, the amount of such metal co-catalystswhich can be present in the polyurethane-producing reaction mixture iswithin the range from about 0.05 to about 2 parts by weight per 100parts by weight of the polyether polyol reactant.

Foaming is accomplished by the presence in the reaction mixture ofvarying amounts of a polyurethane blowing agent such as water which,upon reaction with isocyanate generates carbon dioxide in situ, orthrough the use of blowing agents which are vaporized by the exotherm ofthe reaction, or by a combination of the two methods. These variousmethods are known in the art. Thus, in addition to or in place of water,other blowing agents which can be employed include methylene chloride,liquefied gases which have boiling points below 80° F. and above -60°F., or other inert gases such as nitrogen, carbon dioxide added as such,methane, helium and argon. Suitable liquefied gases include aliphaticand cycloaliphatic fluorocarbons which vaporize at or below thetemperature of the foaming mass. Such gases are at least partiallyfluorinated and may also be otherwise halogenated. Fluorocarbon blowingagents suitable for use in foaming the formulations of this inventioninclude trichlorofluoromethane, dichlorodifluoromethane,1,1-dichloro-1-fluoroethane,1,1,1-trifluoro-2-fluoro-3,3-difluoro-4,4,4-trifluorobutane,hexafluorocyclobutene and octafluorocyclobutane. The generally preferredmethod of foaming for producing flexible foams is the use of water or acombination of water plus a fluorocarbon blowing agent such astrichlorofluoromethane.

The amount of blowing agent employed will vary with factors such as thedesired density of the foamed product. Usually, however, from about 1 toabout 30 parts by weight of the blowing agent per 100 parts by weight ofthe polyether polyol reactant is preferred. Foam densities may be withinthe range from about 0.8 to about 5 pounds per cubic foot (pcf).Polyurethane foam of relatively low density such as 2 pcf and less isusually prepared employing blowing agent comprising water in an amountof at least about 3 parts by weight per 100 parts by weight of polyetherpolyol reactant, whereas higher density foam is provided at lower levelsof water with and without the use of an auxiliary fluorocarbon blowingagent. It is to be understood, however, that these are generalguidelines and that the choice of the particular amount of blowing agentemployed to obtain a desired foam density specification varies fromformulation to formulation and is well within the skill of the art towhich the present invention pertains.

The flame-retardants that can be employed in producing flame-retardedflexible polyether foams in accordance with the teachings of thisinvention can be chemically combined in one or more of the othermaterials used (e.g., in the polyether polyol or polyisocyanate), orthey can be used as discrete chemical compounds added as such to thefoam formulation. The organic flame-retardants preferably containphosphorus or halogen, or both phosphorus and halogen. Usually, thehalogen, when present, is chlorine and/or bromine. Flame-retardants ofthe discrete chemical variety include:2,2-bis(bromomethyl)-1,3-propanediol (also known as dibromoneopentylglycol); 2,3-dibromopropanol, tetrabromophthalic anhydride; brominatedphthalate ester diols such as those produced from tetrabromophthalicanhydride, propylene oxide and propylene glycol; tetrabromobisphenol-A;2,4,6-tribromophenol; pentabromophenol; brominated anilines anddianilines; bis(2,3-dibromopropyl)ether of sorbitol; tetrachlorophthalicanhydride; chlorendic acid; chlorendic anhydride; diallyl chlorendate;chlorinated maleic anhydride; tris(2-chloroethyl)phosphate [(ClCH₂ CH₂O)₃ P(O)]; tris(2,3-dibromopropyl)phosphate;tris(2,3-dichloropropyl)phosphate;tris(1-bromo-3-chloroisopropyl)phosphate; bis(2,3-dibromopropyl)phosphoric acid or salts thereof; oxypropylated phosphoric andpolyphosphoric acids; polyol phosphites such as tris(dipropyleneglycol)phosphite; polyol phosphonates such as bis(dipropyleneglycol)hydroxymethyl phosphonate; di-poly(oxyethylene)hydroxymethylphosphonate; di-poly(oxypropylene)phenyl phosphonate;di-poly(oxypropylene)chloromethyl phosphonate;di-poly(oxypropylene)butyl phosphonate; andO.O-diethyl-N,N-bis(2-hydroxyethyl)aminomethyl phosphonate. Alsosuitable are compounds having the formulas: ##STR33## which are availabefrom Monsanto Chemical Company under the names Phosgard 2XC-20 andPhosgard C-22-R, respectively. Other suitable flame-retardants comprisehalogen-containing polymeric resins such as polyvinylchloride resins incombination with antimony trioxide and/or other inorganic metal oxidessuch as zinc oxide, as described in U.S. Pat. Nos. 3,075,927; 3,075,928;3,222,305; and 3,574,149. It is to be understood that otherflame-retardants known to the art may be used and that the aforesiadcompounds may be employed individually or in combination with oneanother.

Those of the above flame-retardants of the discrete chemical compoundvariety which contain groups reactive with hydroxyl or isocyanate groupscan be used as reactants in producing the polyether polyol reactant orthey can be reacted with organic polyisocyanates, to produce modifiedpolyols or polyisocyanates having chemically combined flame-retardinggroups. Such modified polyether polyols and polyisocyanates are alsouseful as reactants in the process of this invention. In such cases, dueregard must be given to the possible effect of the functionality of thecompound on the other properties (e.d., degree of flexibility) of theresulting foam.

The flame-retarding agent can be used in an amount from about 1 to about30 parts by weight per 100 parts by weight of the polyether polyolreactant, and is usually employed in an amount of at least about 5 partsby weight. It is evident that the particular amount of flame-retardantemployed depends largely on the efficiency of any given agent inreducing flammbility.

The polyether-based polyurethane foams of this invention may be formedin accordance with any of the processing techniques known to the artsuch as, in particular, the "one-shot" technique. In acccordance withthis method, foamed products are provided by carrying out the reactionof the polyisocyanate and polyether polyol simultaneously with thefoaming operation. It is sometimes convenient to add the foamstabilizing component comprising the cyanoalkoxyalkyl and/orcyanoalkoxyalkoxy-substituted polyalkylsiloxane polyoxyalkylenecopolymers of the present invention to the reaction mixture as apremixture with one or more of the blowing agent, polyether polyol,amine catalyst and, when used, the flame-retardant. It is to beunderstood that the relative amount of the various components of thefoam formulations are not narrowly critical. The polyether polyol andpolyisocyanate are present in the foam-producing formulation in a majoramount. The relative amounts of these two components is the amountrequired to produce the urethane structure of the foam and such relativeamounts are well known in the art. The source of the blowing action suchas water, auxiliary blowing agents, amine cataylst, metal co-catalystsand the foam stabilizing admixtures of the present invention are eachpresent in a minor amount necessary to achieve the function of thecomponent. Thus, the blowing agent is present in an amount sufficient toform the reaction mixture, the amine catalyst is present in a catalyticamount (i.e., an amount sufficient to catalyze the reaction to producethe urethane at a reasonable rate), and the cyano-bearing organosiliconepolymers of this invention are present in a foam-stabilizing amount,that is, in an amount sufficient to stabilize the foam. The preferredamounts of these various components are as given hereinabove.

If desired, other additional ingredients can be employed in minoramounts in producing the polyurethane foams in accordance with theprocess of this invention. Illustrative of such additives that can beemployed are: cross-linking agents such as glycerol, triethanolamine andtheir oxyalkylene adducts, as well as fillers, dyes, pigments,anti-yellowing agents and the like. The polyurethanes produced inaccordance with the present invention are used in the same areas asconventional flexible polyether polyurethanes and are especially usefulwhere improved fire-resistance properties are beneficial. Thus, thefoams of the present invention are used with advantage in themanufacture of textile interliners, cushions, mattresses, paddingscarpet underlay, packaging, gaskets, sealers, thermal insulators and thelike.

The following examples are merely illustrative of the present inventionand are not intended as a limitation upon the scope thereof.

It is to be understood that in the formulas included in the data whichfollows, "Me" designates a methyl group, --CH₃.

In the following Examples 1-8, illustrative copolymers of the inventionwere prepared by the following methods:

1. Hydrosilation of allyl-endblocked polyethers with3-(2-cyanoethoxy)propyl-substituted polymethylsiloxane hydrides havingthe average composition, ##STR34## where Me is methyl and x, y and zhave average values within the ranges previously defined herein; and

2. Hydrosilation of the allyl-endblocked polyether reactant and allyl2-cyanoethyl ether with polymethylsiloxane hydrides having the averagecomposition: ##STR35## wherein the sum y+z corresponds to the combinednumber of Y and Z units desired in the final polymeric composition forevery two moles of M units.

As expressed in the examples, the values given for the found weightpercentages of Me(H)SiO content of the various siloxane hydrides(referred to for brevity as "Si-H Fluids") are derived from Si--Hanalyses thereof (cc. H₂ per gram of fluid) in accordance with theconversion: ##EQU2## where the factor 373.3 is the theoretical number ofcubic centimeters of hydrogen provided per gram of fluid consisting of100 percent Me(H)SiO (that is, 22,400 cc. of hydrogen divided by theunit molecular weight of 60). The theoretical percentages of Me(H)SiOcorrespond to the calculated weight [60 (z) or 60 (x+z)] contributed byMe(H)SiO divided by the calculated total molecular weight of the fluidproduct times 100.

In preparing Surfactants A through H as described in accordance with thefollowing Examples 1-8, respectively, the polyether reactants employedwere allyl alcohol-started poly(oxythylene-oxypropylene) ethers cappedwith a methyl group, containing a small percentage (up to about 10 moleper cent) of hydroxy-terminated polyester chains due to incompletemethyl capping of the allyl-endblocked polyether intermediate. Forconvenience the particular reactants employed are designated asPolyethers A and B and have the respective average compositions given inTable I:

                  TABLE I                                                         ______________________________________                                        POLYETHER REACTANTS                                                           General Formula: MeO(C.sub.3 H.sub.6 O).sub.m (C.sub.2 H.sub.4 O).sub.n       CH.sub.2 CHCH.sub.2                                                           ______________________________________                                                Allyl       Molecular                                                 Polyether                                                                             Analysis.sup.1                                                                            Weight.sup.2                                                                             m       n                                      ______________________________________                                        A       1.42        2887.sup.3 28.1    26.9                                   B       1.38        2971.sup.4 30      26.4                                   ______________________________________                                         .sup.1 Weight Percent.                                                        .sup.2 Based on allyl analysis.                                               .sup.3 Oxyethylene content = about 42 weight percent.                         .sup.4 Oxyethylene content = about 40 weight percent.                    

EXAMPLE 1 PREPARATION OF SURFACTANT A A. Preparation of Si-H Fluid I

To a one-liter capacity three-necked flask fitted witn a mechanicalstirrer, water cooled condenser, and source of nitrogen, the followingreactants were added:

1. Trimethylsiloxy-endblocked dimethylsiloxy trimer, Me₃ SiO(Me₂ SiO)₃SiMe₃ is an amount of 19.2 grams, corresponding to 0.1 mole of Me₃SiO_(1/2) and 0.15 mole of Me₂ SiO_(2/2) ;

2. Polymeric methylsiloxy hydride in an amount of 75.0 grams,corresponding to 1.25 moles of Me(H)SiO_(2/2) ;

3. Cyclic dimethylsiloxane tetramer in an amount of 210.9 grams,corresponding to 2.85 moles of Me₂ SiO_(2/2) ; and

4. Trifluoromethylsulfonic acid catalyst in an amount corresponding to0.2 weight percent, based on the total weight of reactants (1)-(3).After 2 hours of stirring under nitrogen, the reaction mixture washomogeneous. The equilibration reaction was stirred for an additionalfive hours and was then neutralized with 50 grams of sodium bicarbonate,heated to 130° C., sparged with nitrogen, cooled and filtered. Basedupon the relative proportions of reactants (2)-(3), normalised on thebasis of two moles of Me₃ SiO_(1/2), the nominal average composition ofthe resulting polymethylsiloxane hydride is: ##STR36## and thetheoretical weight percent of Me(H)SiO is 24.58. Analysis of the productfor silanic hydrogen provided 88.09 cc. H₂ /gram, corresponding to afound Me(H)SiO content of 23.6 weight percent. Based upon the Si--Hanalysis the average composition of the product is, ##STR37## and isreferred to herein as Si--H Fluid I.

B. Preparation of Surfactant A

The above-described Si-H Fluid I (30.21 grams, 0.119 moles Me(H)SiO) wasreacted with allyl 2-cyanoethyl ether (10.0 grams, 0.090 moles) inxylene solvent (50 grams) in the presence of 10 p.p.m. Pt catalyst addedas chloroplatinic acid at a temperature of 80° C. for about 1 hour. Theresultant 3-(2-cyanoethoxy)propyl-modified Si-H fluid. ##STR38## wasthen combined with Polyether A (110 grams, 0.0381 mole, thestoichiometric amount being 0.029 moles). The mixture was heated toabout 90° C. and while at that temperature 10 p.p.m. of Pt catalyst wasadded. The reaction mixture was heated at 95° C. until essentiallycomplete as indicated by a residual Si--H content (standard fermentationtube technique involving the use of KOH--C₂ H₅ OH--H₂ O) of 0.2 cc. H₂per 2 ml. sample of product. The reaction mixture was cooled to roomtemperature, neutralized with sodium bicarbonate, filtered and strippedof solvent by rotary vacuum evaporation (about 50° C./5mm.). The liquidreaction product had a Brookfield viscosity (at 25° C.) of 1200centipoise, and is designated herein as Surfactant A. Based upon therelative proportions of Si--H Fluid I, allyl cyanoethyl ether andstoichiometric amount of Polyether A, Surfactant A comprises a polymerhaving the average composition, ##STR39##

EXAMPLE 2 PREPARATION OF SURFACTANT B A. Preparation of Si-H Fluid II

The equilibration reaction and procedure of part (A) of Example 1 wasrepeated employing reactants (1) and (2) as well as thetrifluoromethylsulfonic acid catalyst in the same amounts, and reactant(3) in an amount of 173.9 grams corresponding to 2.35 moles of Me₂SiO_(2/2). Based upon the relative proportions of reactants (1)-(3),normalized on the basis of two moles of Me₃ SiO_(1/2), the nominalaverage composition of the resulting polymethylsiloxane hydride is:##STR40## and the theoretical weight percent of Me(H)SiO is 27.97.Analysis of the product for silanic hydrogen provided 100.04 cc. H₂/gram, corresponding to a found Me(H)SiO content of 26.8 weight percent.Based upon the Si--H analysis, the average composition of the product,referred to herein as Si--H Fluid II, is ##STR41##

B. Preparation of Surfactant B

The above-described Si--H Fluid II (26.81 grams, 0.1198 moles MeHSiO)was reacted with allyl 2-cyanoethyl ether (9.99 grams, 0.0898 moles) inxylene solvent (50 grams) in the presence of 10 p.p.m. Pt catalyst andunder the reaction conditions of part (B) of Example 1. The resultant3-(2-cyanoethoxy)propyl-modified Si--H fluid has the averagecomposition, ##STR42## and was then combined with Polyether A (114grams, 0.0394 mole, the stoichiometric amount required to react withsaid modified Si--H fluid being about 0.030 mole). The platinumcatalyzed hydrosilation of the polyether reactant was effected under thereaction conditions of part (B) of Example 1, until the residual Si--Hcontent of the mixture was 0.3 cc. H₂ /1 cc. of product. After beingsimilarly neutralized and stripped of solvent, the liquid reactionproduct had a Brookfield viscosity (at 25° C.) of 1080 centipoise, andis designated herein as Surfactant B. Based upon the relativeproportions of Si--H Fluid II, allyl cyanoethyl ether and stoichiometricamount of Polyether A, Surfactant B comprises a polymer having theaverage composition, ##STR43##

EXAMPLE 3 PREPARATION OF SURFACTANT C A. Preparation of Si--H Fluid III

Equilibration of a reaction mixture containing the following reactants(1)-(3) was effected in the presence of trifluoromethylsulfonic acidcatalyst (0.7 grams) employing the reaction conditions and proceduretypically illustrated by part (A) of Example 1:

1. Hexamethyldisiloxane, Me₃ SiOSiMe₃, in an amount of 8.1 grams (0.05mole) corresponding to 0.1 mole of Me₃ SiO_(1/2) ;

2. Polymeric methylsiloxane hydride in an amount of 42.0 grams,corresponding to 0.7 mole of Me(H)SiO_(2/2) ; and

3. Cyclic dimethylsiloxane tetramer in an amount of 240.5 grams,corresponding to 3.25 moles of Me₂ SiO_(2/2). Based upon the relativeproportions of reactants (1)-(3), normalized on the basis of two molesof Me₃ SiO_(1/2), the nominal average composition of the resultingpolymethylsiloxane hydride is: ##STR44## and the theoretical weightpercent of Me(H)SiO is 14.45. As used in part (B) of this example,analysis of the product for silanic hydrogen provided 53.0 cc. H₂ /gram,corresponding to a found Me(H)SiO content of 14.17 weight percent. Basedupon the Si--H analysis, the product has the average composition##STR45## and is referred to as Si--H Fluid III.

B. Preparation of Surfactant C

A reaction mixture was prepared containing the following:

a. Si--H Fluid III in an amount of 25 grams (0.059 mole of MeHSiO);

b. Polyether B in an amount of 84.3 grams (0.0284 mole);

c. Allyl 2-cyanoethyl ether in an amount of 4.4 grams (0.0396 mole); and

d. Xylene solvent (100 ml.)

Based upon a stoichiometric reaction involving hydrosilation ofreactants (b) and (c) in a mole ratio of 5:8.7, the respective amountsof the unsaturated reactants in excess of stoichiometry were about 31mole percent for reactant (b) and about 5.8 mole percent for reactant(c). The reaction mixture was heated to 83° C. and was then catalyzed bythe addition of 50 p.p.m. Pt catalyst, the addition of which raised thetemperature to 97° C. The reaction mixture was held at 100° C. for atotal reaction time of 2.75 hours during which time samples of thereaction mixture were analyzed for residual Si--H content. At the end of1.75 hours of elapsed reaction time, an additional amount (about 8weight percent of the initial charge) of reactants (b) and (c) wasadded. At the end of 2.5 hours of total elapsed reaction time, residualSi--H was 0.65 cc. H₂ /2 cc. sample. The reaction mixture was thencooled, neutralized with sodium bicarbonate, filtered and stripped ofsolvent. The reaction product (112 grams) was a clear, dark liquidhaving a Brookfield viscosity (at 25° C.) of 870 centipoise, and isdesignated herein as Surfactant C. Based upon the average composition ofSi--H Fluid III and the aforesaid stoichiometry, Surfactant C comprisesa copolymer having the following average composition, ##STR46## Inaddition to the hydrosilation of unsaturated reactants (b) and (c)proceeding concurrently at substantially the same reaction rate, thehydrosilation may also occur concurrently at different reaction rates orit may proceed to first hydrosilate substantially all of either reactant(b) or reactant (c) followed by reaction of remaining silanic hydrogenwith the other of the unsaturated reactants. Irrespective of therelative rates of reaction, however, the average composition ofSurfactant C is within the scope of the polymers provided by the presentinvention. Thus, if the relative rates of reaction between silanichydrogen of reactant (a) and respective reactants (b) and (c) are suchthat the desired stoichiometry was not achieved, the average number ofthe 3-(2-cyanoethoxy)propyl methylsiloxy Y units (that is, the value ofy) contained in Surfactant C is within the range from about 7.1 to about9.2, and the average number of the polyether-substituted Z units (thatis, the value of z) is correspondingly within the range from about 6.6to about 4.5. These limits of y and z are readily calculated. Forexample, hydrosilation of the total initial charge (0.0284 mole) ofreactant (b) leaves 0.0306 mole of Si--H for reaction with (c) and thusthe average value of y is 7.1 [that is, 0.0306/0.059 times 13.7] , and zhas a corresponding average value of 6.6. Likewise, hydrosilation of thetotal initial charge (0.0396) of reactant (c), provides a polymercomposition in which the average value of y is 9.2 [that is,0.0396/0.059 times 13.7] and the corresponding average value of z is4.5. Partial hydrosilation of reactants (b) and (c) provides polymerproducts in which the average value of y is intermediate 7.1 and 9.2 inwhich the corresponding value of z is intermediate 6.6 and 4.5.

EXAMPLE 4 PREPARATION OF SURFACTANT D A. Preparation of Si--H Fluid IV

To a one liter, three-necked flask equipped with a mechanical stirrer,condenser and nitrogen blow-by, the following reactants were added:

1. Hexamethyldisiloxane, Me₃ SiOSiMe₃, in an amount of 16.2 grams (0.1mole);

2. Polymeric methylsiloxane hydride in an amount of 120 grams,corresponding to 0.2 mole of Me(H)SiO_(2/2) ; and

3. Cyclic dimethylsiloxane tetramer in an amount of 518 gramscorresponding to 0.7 mole of Me₂ SiO_(2/2).

The mixture was equilibrated in the presence of trifluoromethylsulfonicacid catalyst (2 grams) for several days. The viscous reaction mixturewas then sparged with nitrogen, stirred with sodium bicarbonate forabout 3 hours, heated at 120° C. for several hours and filtered. Basedupon the relative proportions of reactants (1)-(3) normalized on thebasis of two moles of Me₃ SiO_(1/2), the nominal average composition ofthe polymethylsiloxane hydride is: ##STR47## and the theoretical contentof Me(H)SiO is 18.34 weight percent. As used in part (B) of thisexample, analysis of the product for silanic hydrogen provided 66.6 cc.H₂ /gram, corresponding to a found Me(H)SiO content of 17.84 weightpercent. Based upon the Si--H analysis, the product has the averagecomposition, ##STR48## and is referred to herein as Si--H Fluid IV.

B. Preparation of Surfactant D

The purpose of this preparation was to react 70 mole percent of thesilanic hydrogen of Si--H Fluid IV with allyl 2-cyanoethyl ether and theremaining 30 percent with Polyether B. To this end, allyl 2-cyanoethylether was used in a total amount (0.0542 moles) which included about a 5mole percent excess over the desired stoichiometry and Polyether B wasused in a total amount (0.0299 moles) which included about 35 molepercent excess.

A reaction mixture was prepared containing:

a. Si--H Fluid IV in an amount of 25 grams, corresponding to 0.074 moleof Me(H)SiO;

b. Polyether B in an amount of 80.9 grams (0.0272 mole);

c. Allyl 2-cyanoethyl ether in an amount of 5.4 grams (0.0488 mole); and

d. Xylene (100 ml.).

After heating the reaction mixture to 84° C., 50 p.p.m. Pt catalyst wasadded. The reaction temperature rose to 100° C. and was maintained at100° C. for 1.25 hours after which further catalyst (50 p.p.m.) wasadded. After a total reaction time of 3.4 hours, a further charge ofPolyether B (8.0 grams; 0.0027 mole), allyl 2-cyanoethyl ether (0.6gram; 0.0054 mole), xylene (10 ml.) and catalyst (0.08 ml.) was added tothe reaction. The reaction mixture was then refluxed (143° C.) for 2hours. The mixture was then cooled, neutralized, filtered and desolvatedto provide a clear liquid product (106.5 grams), referred to herein asSurfactant D, having a Brookfield viscosity (at 25° C.) of 1380centipoise. Analysis of the product showed about 85 percent reaction ofthe silanic hydrogen of Si--H Fluid IV. Based upon the averagecomposition of Si--H Fluid IV and the aforesaid desired stoichiometry,Surfactant D comprises a copolymer having the following averagecomposition, ##STR49## In the event the reaction between silanichydrogen of reactant (a) with the unsaturated reactants occurred atother than the desired stoichiometry, the average number of3-(2-cyanoethoxy)propyl methylsiloxy units contained in Surfactant D iswithin the range from about 11.6 to about 14.3, and the average numberof polyether-methylsiloxy units is corresponding within the range fromabout 7.9 to about 5.2.

EXAMPLE 5 PREPARATION OF SURFACTANT E

The purpose of this preparation was to react 70 mole percent of thesilanic hydrogen of Si--H Fluid IV prepared as described under part (A)of Example 4 above with allyl 2-cyanoethyl ether and the remaining 30percent with Polyether B. To this end, the allyl 2-cyanoethyl ether wasused in a total amount (0.0542 moles) which included about a 5 molepercent excess over the desired stoichiometry and Polyether B was usedin a total amount (0.0299 moles) which included about 35 mole percentexcess.

A reaction vessel was charged with Si--H Fluid IV in an amount of 25grams, corresponding to 0.074 mole of Me(H)SiO, and 25 ml. of xylene. Tothis solution, there was then added dropwise over a two hour period, amixture containing: (1) allyl 2-cyanoethyl ether (6.0 grams, 0.0542mole); (2) Polyether B (68.3 grams, 0.023 mole); (3) 50 p.p.m. Ptcatalyst; and 75 ml. of xylene. During the addition, the reactiontemperature was maintained at 85° C. After about 20 minutes, anadditional charge of Polyether B (20.5 grams, 0.0069 mole), Pt catalystand xylene (10 ml.) was added dropwise over 0.75 hour. The reactionmixture was continued to be maintained at 85° C. for another hour afterwhich the product was cooled, neutralized, filtered and stripped. Theremaining liquid (111.5 grams) which is referred to herein as SurfactantE, was clear and had a Brookfield viscosity of 1460 centipoise. Analysisof the product showed that about 90 percent of silanic hydrogen of Si--HFluid IV had been reacted. Surfactant E comprises a copolymer to whichthe average composition expressd above for Surfactant D is assigned.

EXAMPLE 6 PREPARATION OF SURFACTANT F A. Preparation of Si--H Fluid V

Equilibration of a reaction mixture containing the following reactants(1)-(3) was effected in the presence of trifluoromethylsulfonic acidcatalyst (1 gram) employing the reaction conditions and proceduretypically illustrated by part (A) of Example 1:

1. Hexamethyldisiloxane, Me₃ SiOSiMe₃, in an amount of 16.2 grams (0.1mole);

2. Polymeric methylsiloxane hydride in an amount of 120.0 grams,corresponding to 2.0 moles of Me(H)SiO_(2/2) ; and

3. Cyclic dimethylsiloxane tetramer in an amount of 370.0 grams,corresponding to 5.0 moles of Me₂ SiO_(2/2).

Based upon the relative proportions of reactants (1)-(3), normalized onthe basis of two mols of Me₃ SiO_(1/2), the nominal average compositionof the resulting polymethylsiloxane hydride is: ##STR50## and thetheoretical weight percent of Me(H)SiO is about 23.7 weight percent.Inasmuch as analysis of this product provided 94.0 cc. H₂ /gramcorresponding to 25.2 weight percent Me(H)SiO, for the purpose of thisexample the composition of Si--H Fluid V is taken as expressed above.

B. Preparation of Surfactant F

In this preparation, the following reactants were employed:

a. Si--H Fluid V prepared in accordance with part (A) of this example,in an amount of 25 grams corresponding to 0.099 mole of Me(H)SiO2/2;

b. Allyl 2-cyanoethyl ether in an amount of 8.0 grams (0.072 mole)corresponding to the amount required to achieve a stoichiometricreaction with 72.5 mole percent of silanic hydrogen contained inreactant (a);

c. Polyether B in an amount of 80.8 grams (0.027 mole), corresponding tothe minimum amount required to react with the remaining silanic hydrogencontained in reactant (a); and

d. Polyether B in an additional amount of 24.2 grams, corresponding toabout a 30 mole percent excess over the desired stoichiometric reaction.

In effecting the hydrosilation, reactants (a), (b) and (c) were combinedwith 100 ml. xylene and heated to 85° C. Platinum catalyst (50 p.p.m.Pt) as chloroplatinic acid in 20 ml. xylene was added dropwise over 0.5hour. The reaction mixture exothermed to 98° C. After this initialreaction period, greater than 85 percent of Si--H had been consumed. Thetemperature was then held at 85° C. while a solution of reactant (d), Ptcatalyst (50 p.p.m. Pt) and 20 ml. xylene was added dropwise over onehour. After this period, greater than 92.5 percent of silanic hydrogenhad been consumed and thus the reaction was terminated. Afterneutralization, filtration and removal of solvent, the liquid product(132.5 grams) which is referred to herein as Surfactant F, had aviscosity of 1000 centipoise. Based upon the average nominal compositionof Si--H Fluid V and the desired stoichiometry, Surfactant F comprises apolymer to which the following average composition is assigned,##STR51##

EXAMPLE 7 PREPARATION OF SURFACTANTS G-1 and G-2 A. Preparation of Si--HFluid VI

In this preparation, the reaction mixture contained:

1. Hexamethyldisiloxane, Me₃ SiOSiMe₃, in an amount of 16.2 grams (0.1mole);

2. Polymeric methylsiloxane hydride in an amount of 120 grams,corresponding to 2.0 moles of Me(H)SiO_(2/2) ; and

3. Cyclic dimethylsiloxane tetramer in an amount of 444 gramscorresponding to 6.0 moles of Me₂ SiO_(2/2). The mixture wasequilibrated in the presence of trifluoromethylsulfonic acid catalyst (2grams) for several days while magnetically stirred. The mixture was thentreated with sodium bicarbonate, mechanically stirred and sparged withnitrogen for 2 hours, and heated at 120° C. for about 4 hours whilesparging which was continued overnight. The mixture was then filtered.Based upon the relative proportions of reactants (1)-(3), normalized onthe basis of two moles of Me₃ SiO_(1/2), the nominal average compositionof the resulting polymethylsiloxane hydride is, ##STR52## and thetheoretical weight percent of Me(H)SiO is 20.66. Analysis of the productfor silanic hydrogen provided 74.6 cc. H₂ /gram corresponding to a foundMe(H)SiO content of 19.98 weight percent. Based upon the Si--H analysis,the average composition of the product is ##STR53##

B. Preparation of Surfactants G-1 and G-2

In these preparations, a reaction mixture containing the following wasused:

a. Si--H Fluid VI prepared under part (A) of this example in an amountof 25 grams (0.0832 mole Me(H)SiO);

b. Polyether B (86.2 grams, 0.0290 mole);

c. Allyl 2-cyanoethyl ether (8.1 grams, 0.0728 mole); and

d. Toluene (100 ml.)

Based upon the desired stoichiometric reaction which was to react (b)and (c) in a mole ratio of 5.3:14, the respective amounts of theunsaturated reactants in excess of stoichiometry were 27 mole percent ofreactant (b) and about 30 mole percent of reactant (c). The reactionmixture was heated for 2 hours at 90° C. with stirring during which 100p.p.m. Pt catalyst was added in three increments, namely, initially (50p.p.m.), after 60 minutes (25 p.p.m.) and after 90 minutes (25 p.p.m.)of total reaction time. After 10 minutes of elapsed reaction time, thestandard test for residual Si--H showed that greater than 96 percent hadbeen consumed and after the two hour total reaction period, the reactionwas essentially complete (greater than 97.5 percent Si--H consumed). Theliquid product was then neutralized with sodium bicarbonate, filteredand desolvated by rotary evaporation. About one half of the total liquidproduct (121.5 grams) was vacuum-sparged with nitrogen. The spargedproduct had a Brookfield viscosity of 1980 centipoise, and is referredto herein as Surfactant G-1. The remaining product, recovered withoutsparging, had a viscosity of 1300 centipoise, and is referred to hereinas Surfactant G-2. Based upon the average composition of Si--H Fluid VIand the aforesaid stoichiometry, Surfactants G-1 and G-2 comprisepolymers having the following average composition, ##STR54## In theevent the reaction between silanic hydrogen of reactant (a) with theunsaturated reactants occurred at other than the desired stoichiometry,the average number of 3-(2-cyanoethoxy)propyl methylsiloxy unitscontained in Surfactants G-1 and G-2 is within the range from about 12.6to about 16.8 and the average number of the polyethermethylsiloxy unitsis correspondingly within the range from about 6.7 to about 2.5.

EXAMPLE 8 PREPARATION OF SURFACTANT H

The reaction of this example was carried out in a 500 liter, 3-neckedflask equipped with magnetic stirrer, thermometer, nitrogen inlet andheating mantle to which the following were charged:

a. Si--H Fluid III prepared as described under part (A) of Example 3above in an amount of 25 grams (0.059 mole Me(H)SiO);

b. Polyether B in an amount of 83.1 grams (0.028 mole);

c. Allyl 2-cyanoethyl ether in an amount of 5.0 grams (0.045 mole); and

d. Toluene solvent (100 ml.).

Based upon a stoichiometric reaction involving hydrosilation ofreactants (b) and (c) in a mole ratio of 5:8.7, the respective amountsof the unsaturated reactants in excess of stoichiometry were 30 molepercent of reactant (b) and 20 mole percent of reactant (c). Thereaction mixture was heated for 1 hour at 90° C. with stirring duringwhich time 100 p.p.m. Pt catalyst was added in four equal increments,namely, initially, and after 10, 30 and 40 minutes of elapsed reactiontime. After 20 minutes of elapsed reaction time, the standard test forresidual Si--H showed that greater than 98.5 percent had been consumed,and after 50 minutes of elapsed reaction time, the test for residualSi--H was negative. After cooling and neutralization with sodiumbicarbonate (20 grams), the product was filtered and desolvated byrotary evaporation up to 50° C./1 mm. mercury pressure. The liquidreaction product (105.5 grams) had a Brookfield viscosity (at 25° C.) of1360 centipoise, and is referred to herein as Surfactant H. Based uponthe average composition of Si--H Fluid III and the aforesaidstoichiometry, Surfactant H comprises a copolymer having the followingaverage composition, ##STR55## In the event the reaction between silanichydrogen of reactant (a) with the unsaturated reactants occurred atother than the desired stoichiometry, the average number of3-(2-cyanoethoxy)propyl methylsiloxy units contained in Surfactant H iswithin the range from about 7.2 to about 10.4, and the average number ofpolyether-methylsiloxy units is correspondingly within the range fromabout 6.5 to about 3.3.

In accordance with the following Examples 9 through 28, flexiblepolyether polyurethane foams were produced using the above-describedSurfactants A through H of the present invention as the respective foamstabilizing surfactant component of the foam-producing reaction mixture,designated herein as Foam Formulation A, which had the followingcomposition:

                  TABLE II                                                        ______________________________________                                        FOAM FORMULATION A                                                            Component                Parts By Weight                                      ______________________________________                                        Polyether Polyol having a hydroxyl                                            number of 56 produced by reacting                                                                      100                                                  glycerol and propylene oxide                                                  Tolylene Diisocyanate (Index 105).sup.1                                                                49.73                                                Tris(2-chloroethyl)phosphate                                                                           10                                                   Water                    4                                                    Bis[2-(N,N-dimethylamino)ethyl] ether                                                                  0.1                                                  employed as a 70 weight per cent solution                                     in dipropylene glycol                                                         Stannous Octoate         0.35                                                 Surfactant               Varied.sup.2                                         ______________________________________                                         .sup.1 This component was a mixture of the 2,4- and 2,6- isomers of           tolylene diisocyanate present in a weight ratio of 80:20, respectively.       Index 105 designates that the amount of mixture employed was 105 weight       percent of the stoichiometric amount required to react with total reactiv     hydrogens from the polyether polyol and water present in the foam             formulation.                                                                  .sup.2 For specific proportions employed, refer to Tables III-VII herein.

Foam Formulation A was also used as the reaction mixture for providingflexible polyether polyurethane foams stabilized with other surfactants,designated herein as Surfactants AA, BB and BB-1 which are not withinthe scope of the present invention. These particular surfactants areidentified below:

Surfactant AA is a hydrolyzable polyoxyalkylenepolysiloxane blockcopolymer having the following average structure, wherein thepolyoxyalkylene block is derived from a butanol-started,hydroxyl-terminated poly(oxyethyleneoxypropylene) ether:

    MeSi[(OSiMe.sub.2).sub.6.4 (OC.sub.2 H.sub.4).sub.19 (OC.sub.3 H.sub.6).sub.14 OC.sub.4 H.sub.9 ].sub.3

and was employed in undiluated (that is, 100 percent active) form.

Surfactant BB is a polyoxyalkylene-polysiloxane block copolymer havingthe average composition, ##STR56## and was employed in undiluted or 100percent active form.

Surfactant BB-1 is a solution containing 55 weight percent of SurfactantBB (that is, 55 weight percent active) and 45 weight percent of asolvent mixture consisting of 90 weight percent of the butanol-startedpolyether mono-ol having the average formula, C₄ H₉ O(C₂ H₄ O)₁₁ (C₃ H₆O)₈ H, and 10 weight percent of an ethylene oxide adduct of nonylphenolhaving the average structure, C₉ H₁₉ C₆ H₄ O(C₂ H₄ O)₁₀.5 H.

General Foaming Procedure

The manipulative steps involved in preparing the foams of Examples 9 to28 as well as the other foam preparations described herein including thecontrol foams, are as follows: After dispensing the polyether polyol ina container (Lily Cup No. 32TN6), the flame-retardant (when used) isadded thereto and dispersed therein with a spatula. The surfactant isthen added from a syringe and is also dispersed with a spatula. Afterinserting a baffle, a premixture of the amine catalyst and blowing agentis added but not dispersed. The container containing the aforesaidmixture is then placed in a drill press and the mixture agitated 15seconds at 2000 revolutions per minute, after which the stannous octoateco-catalyst is added from a syringe. After mixing for an additional 8seconds, the diisocyanate reactant is added rapidly and the agitation iscontinued for another 7 seconds. After the mixing cycle, the mixture ispoured into a parchment-lined container (12 × 12 × 12 inches) supportedby a wooden mold. The foam is allowed to rest in the container for atleast 3 minutes and is then cured for 15 minutes at 130° C. Aftercutting, the height of the foam rise is measured, and foam samples areprepared for various physical property determinations including burningextent in the case of the flame-retarded foam products.

As used in the data which follows, the following terms have theindicated significance:

"Rise" denotes the foam height and is directly proportional to potencyof the surfactant.

"Breathability" denotes foam porosity and is roughly proportional to thenumber of open cells in the foam. As reported herein, breathability wasdetermined in accordance with the NOPCO test procedure described by R.E. Jones and G. Fesman, "Journal of Cellular Plastics" (January, 1965),as follows: A 2 inch × 2 inch × 1 inch piece of foam is cut from nearthe center of the bun. Using a Nopco Foam Breathability Tester, TypeGP-2 Model 40GD10, air is drawn through the foam sample at a pressuredifferential of 0.5 inches of water less than atmospheric pressure. Theair flow is parallel to the direction of original foam rise. The degreeof openness of the foam (or foam breathability) is measured by the rateof air flow through the foam and is reported in standard cubic feet perminute (SCFM).

"CPI" denotes "cells per inch", that is, the number of cells per linearinch of the foam. CPI is directly proportional to the fineness of thecell structure.

"Burning Extent" was determined in accordance with standard flammabilitytest procedure ASTM D-1692-68 except that five test specimens of foamwere used instead of ten. Burning extent denotes the burned length (ininches) of the foam and is reported as the average of the resultsobtained with the various test specimens of a given foam. On the basisof this test, an average burning extent of less than 5.0 inchesqualifies the foam for a self-extinguishing ("SE") rating. When theburning extent of at least one test specimen is 5.0 inches or greater,the foam is assigned a burning ("B") rating and usually no furtherspecimens of that foam are tested.

"Burning Time" denotes the average time (in seconds) taken to give thespecified burning extent.

EXAMPLES 9-10

In these examples Surfactants A and B produced in accordance withExamples 1 and 2 above, were employed as the "surfactant" component offlame-retarded Foam Formulation A at a concentration of one part byweight per 100 parts of polyol reactant. The results are given in TableIII which also includes corresponding data as control Run No. 1 based onSurfactant AA which was also employed as the surfactant component ofFoam Formulation A in a concentration of one part by weight.

                  TABLE III                                                       ______________________________________                                              Surf-           Breath-                                                                              Burning                                                                              Burning                                         act-   Rise     ability                                                                              Extent Time                                      Ex.   ant    (inches) (SCFM) (inches)                                                                             (seconds)                                                                            Rating                             ______________________________________                                        9     A      7.3      6.1    3      48     SE                                 10    B      7.1      6.0    2.4    40     SE                                 Run                                                                           K-1   AA     7.2      6.0    6      63     B                                  ______________________________________                                    

The results of Table III show that Surfactants A and B provided foam ofsubstantially lower burning extent than control Surfactant AA which isotherwise an excellent stabilizer of polyether polyol-based urethanefoam.

EXAMPLES 11-16

In these examples, Surfactant C prepared in accordance with Example 3above was employed as the surfactant component of Foam Formulation A ina concentration of 0.3, 0.5 and 0.6 parts per 100 parts of polyol.Control foams were also prepared (Runs K-2 to K-4) based onabove-identified Surfactant BB as the surfactant component of the sameformulation at concentrations of 0.3 and 0.5 parts per 100 parts ofpolyol. The results of these examples and control runs are given inTable IV which follows.

                                      TABLE IV                                    __________________________________________________________________________    Example     --   11   12   --   13   --   14   15   --    16                  __________________________________________________________________________    Control Run K-2  --   --   K-3  --   K-4  --   --   K-5   --                  Surfactant  BB.sup.1                                                                           C    C    BB.sup.1                                                                           C    BB.sup.1                                                                           C    C    BB.sup.1                                                                            C                   Parts by weight                                                                           0.3  0.3  0.6  0.5  0.5  0.3  0.3  0.6  0.3   0.3                 Rise, inches                                                                              7.4  7.2  7.5  7.7  7.6  7.4  7.3  7.5  7.5   7.5                 Breathability, SCFM                                                                       4.0  4.3  3.3  3.5  3.3  3.9  4.0  3.2  4.0   4.5                 Top Collapse, inches                                                                      None None None None None None None None None  None                CPI         35-40                                                                              35-40                                                                              35-40                                                                              35-40                                                                              35-40                                                                              35-40                                                                              35-40                                                                              40-45                                                                              30-35 30-35               Density, lbs./ft..sup.3                                                                   1.66 1.65 1.64.sup.2                                                                         1.62 1.64 1.63 1.68 1.66.sup.2                                                                         1.62  1.68                Burning extent, inches                                                                    3.6  2.4  2.7  3.9  2.2  3.9  2.6  2.6  3.6   2.5                 Burning time, seconds                                                                     55   37   40   63   39   63   42   40   57    39                  __________________________________________________________________________     .sup.1 Not a surfactant of the invention.                                     .sup.2 Basal split.                                                      

Comparison of the results of Example 11 with control K-2, Example 13with control K-3, Example 14 with control K-4 and Example 16 withcontrol K-5, shows that in each instance the foam product stabilizedwith 3-(2-cyanoethoxy)propyl-modified Surfactant C of the inventionburned to a substantially lesser extent than the control foamsstabilized with Surfactant BB in which the polysiloxane backbone issubstituted with methyl groups only. The foam products of Examples 12and 15 stabilized with 0.6 parts of surfactant C exhibited basal splits,but were also of relatively low burning extent and of otherwiseacceptable quality.

EXAMPLES 17-20

In these examples, a series of foams were prepared employing SurfactantsD and E of Examples 4 and 5 above, as the surfactant component of FoamFormulation A in the concentration given in Table V below. The controlfoam for this series was also the foam produced in Run K-4 which, forconvenience, is repeated in Table V which follows.

                                      TABLE V                                     __________________________________________________________________________    Example     --   17   18   19   20                                            __________________________________________________________________________    Control Run K-4  --   --   --   --                                            Surfactant  BB.sup.1                                                                           D    E    D    E                                             Parts by weight                                                                           0.3  0.3  0.3  0.6  0.6                                           Rise, inches                                                                              7.4  7.4  7.4  7.5  7.6                                           Breathability, SCFM                                                                       3.9  4.0  4.3  3.2  3.2                                           Top collapse, inches                                                                      None None None None None                                          CPI         35-40                                                                              25-30                                                                              35-40                                                                              35-40                                                                              40-45                                         Density, lbs./ft..sup.3                                                                   1.63 1.68 1.66 1.66.sup.2                                                                         1.64.sup.2                                    Burning extent, inches                                                                    3.9  3.2  3.2  3.5  3.1                                           Burning time, seconds                                                                     63   56   52   59   51                                            __________________________________________________________________________     .sup.1 Not a surfactant of the invention.                                     .sup.2 Basal split.                                                      

The results of Table V further demonstrate the efficacy of thesurfacants of this invention in providing flame-retardant flexiblepolyether-based foam of relatively low burning extent.

EXAMPLES 21-22

In these examples, foams were prepared employing Surfactant F of Example6 above, as the surfactant component of Foam Formulation A in aconcentration of 1.0 and 0.5 part per 100 parts of polyol. As shown bythe results of the following Table VI, the flame-retarded foam productswere of low burning extent.

                  TABLE VI                                                        ______________________________________                                        Example             21          22                                            ______________________________________                                        Surfactant          F           F                                             Parts by Weight     1.0         0.5                                           Rise, inches        7.6         7.4                                           Breathability, SCFM 4.0         4.4                                           Top collapse, inches                                                                              None        None                                          CPI                 35-40       35-40                                         Density, lbs./ft..sup.3                                                                           1.65        1.67                                          Burning extent, inches                                                                            2.6         2.4                                           Burning time, seconds                                                                             38          38                                            ______________________________________                                    

EXAMPLES 23-28

In accordance with these examples, another series of flame-retardedfoams were provided employing above-described Surfactants G-1, G-2 and Has the surfactant component of Foam Formulation A. The control for thisseries was Run No. K-3. The level of surfactant employed in each foampreparation and the results are set-forth in Table VII which follows.

                                      TABLE VII                                   __________________________________________________________________________    Example     --   23   24   25   26   27   28                                  __________________________________________________________________________    Control Run K-3  --   --   --   --   --   --                                  Surfactant  BB.sup.1                                                                           G-1  G-2  H    G-1  G-2  H                                   Parts by weight                                                                           0.5  0.5  0.5  0.5  1.0  1.0  1.0                                 Rise, inches                                                                              7.7  7.5  7.5  7.5  7.5  7.4  7.7                                 Breathability, SCFM                                                                       3.5  4.8  4.6  3.4  4.1  4.1  2.8                                 Top collapse, inches                                                                      None None None None None None None                                CPI         35-40                                                                              35-40                                                                              35-40                                                                              35-40                                                                              35-40                                                                              30-35                                                                              35-40                               Density, lbs./ft..sup.3                                                                   1.62 1.64 1.68 1.64 1.62 1.64 1.63                                Burning extent, inches                                                                    3.9  2.2  2.5  2.3  2.6  2.7  2.4                                 Burning time, seconds                                                                     63   36   42   39   41   48   36                                  __________________________________________________________________________     .sup.1 Not a surfactant of the invention.                                

Inspection of the data of Table VII indicates that the3-(2-cyanoethoxy)propyl-modified copolymers of the invention providedflame-retarded foam of substantially lower burning extent than the foamstabilized with Surfactant BB in which the polysiloxane backbone issubstituted solely with methyl groups.

EXAMPLES 29-37

In accordance with these examples, a potency determination was made ofsurfactants of this invention employing Foam Formulation B which had thefollowing composition:

                  TABLE VIII                                                      ______________________________________                                        FOAM FORMULATION B                                                            Component              Parts BY Weight                                        ______________________________________                                        Polyether Polyol having a hydroxyl                                                                   100                                                    number of 46 produced by reacting                                             glycerol, propylene oxide and                                                 ethylene oxide                                                                Tolylene Diisocyanate (Index 105).sup.1                                                              57                                                     Blowing Agent                                                                 Water                  4.85                                                   Trichlorofluoromethane 15                                                     Dimethylethanolamine   0.35                                                   Stannous octoate       0.3                                                    Surfactant             0.6                                                    ______________________________________                                         .sup.1 As identified in footnote.sup.1 of Table II.                      

As indicated, Foam Formulation B contains 4.85 parts by weight of waterper 100 parts by weight of polyol reactant. This system is usually moredifficult to stabilize than the more conventional formulationscontaining less water and thus provides a relatively sensitive test ofsurfactant potency. Also included in this series of foam preparationswas the preparation of control foams (Runs K-6 to K-10) employingabove-described Surfactants BB and BB-1 as the surfactant component ofFoam Formulation B. The results are given in Table IX which follows.

                  TABLE IX                                                        ______________________________________                                        Potency Study                                                                 Control                      Breath-  Top                                     and    Sur-       Rise       ability  Collapse                                Example                                                                              factant    (inches)   (SCFM)   (inches)                                ______________________________________                                        K-6    BB.sup.1   11.4       4.1       0.45                                   K-7    BB-1.sup.2 11.8       2.1      0.1                                     29     C          11.3       3.5      0.4                                     K-8    BB-1.sup.2 11.7       2.9      0.1                                     30     C          11.3       4.3      0.5                                     31     D          11.4       3.3      0.3                                     32     E          11.3       3.6      0.4                                     K-9    BB-1.sup.2 11.6       3.3      0.1                                     33     C          11.3       5.5      0.4                                     34     F          10.3       7.5      1.5                                     K-10   BB-1.sup.2 11.7       2.7      Slight                                  35     G-1        10.4       6.2      1.4                                     36     G-2        10.2       6.8      1.5                                     37     H          11.3       4.0      0.6                                     ______________________________________                                         .sup.1 Not a surfactant of the invention; employed in an amount of 0.6        part per 100 parts of polyol reactant contained in Foam Formulation B.        .sup.2 Not a surfactant of the invention; employed as a 55 weight percent     active solution as previously described; therefore, the active polymer        concentration is also about 0.6 part per 100 parts of polyol reactant.   

From the standpoint of foam rise the data of Table IX indicate that thepotency of the surfactants of the invention is acceptable. The data alsoindicate that when used in non flame-retarded Foam Formulation B,overall the surfactants of the invention tend to provide more open foam(as reflected by the higher breathability values) than the comparativesurfactants. In particular, the foams of Examples 34-36 were of a highlyopen, porous nature (breathability = 7.5, 6.2 and 6.8) which may havecontributed to the observed top collapse (about 1.5 inches) of theseparticular foams. On the other hand, in the other examples of Table IXas well as the control runs, the foam products exhibted a minimum of topcollapse, and, as shown by the data of Tables III-VII in which thesurfactants of the invention were employed to stabilize flame-retardedfoam, no settling of the original height of the foam was observed.

In accordance with the following Examples 38 and 39, furtherillustrative cyanoalkoxyalkyl-substitutedpolyalkylsiloxane-polyoxyalkylene copolymers of the invention,designated herein as Surfactants J and K, were prepared. Thesepreparations comprised the platinum-catalyzed hydrosilation reactionbetween 3-(2-cyanoethoxypropyl)-substituted polymethylsiloxane hydrides,referred to respectively as Si--H Fluids VII and VIII, and amethoxy-capped, allyl alcohol-started poly(oxyethylene-oxypropylene)ether (referred to as Polyether C) having the average composition,

    CH.sub.2 ═CHCH.sub.2 (OC.sub.2 H.sub.4).sub.24.9 (OC.sub.3 H.sub.6).sub.25.6 OMe.

The said Si--H reactants were prepared by the equilibration of reactionmixtures containing the following reactants as the source of theindicated units:

Reactant (1): Hexamethyldisiloxane, Me₃ SiOSIMe₃, as the source of theendblocking trimethylsiloxy units, Me₃ SiO_(1/2).

Reactant (2): Cyclic polymers of dimethylsiloxane distilled to providethe cyclic tetramer, [Me₂ SiO]₄, as a source of the dimethylsiloxyunits.

Reactant (3): 3-(2-cyanoethoxy)propylheptamethylcyclotetrasiloxane,

    [(NC-C.sub.2 H.sub.4 O-C.sub.3 H.sub.6)(Me)SiO][(Me).sub.2 SiO].sub.3

as the source of the 3-(2-cyanoethoxy)propyl methylsiloxy units and asan additional source of the dimethylsiloxy units. Illustrative of themanner in which this reactant was prepared is as follows: The cyclictetramer, [(Me)₂ SiO]₃ [(Me)(H)SiO], in an amount of 250 grams washeated to 60° C. followed by the addition thereto of 0.3 ml. of platinumcatalyst solution prepared by the reaction of chloroplatinic acid withoctyl alcohol. Further heating to 90° C. was followed by the addition of97.3 grams of allyl 2-cyanoethyl ether over a period of 15 minutes. Thereaction temperature maintained itself at about 100°-127° C. Thereaction mixture was treated with sodium bicarbonate, filter aid andcharcoal, and was then filtered and vacuum distilled (vacuum strippingis also suitable) to provide the corresponding3-(2-cyanoethoxy)propyl-modified cyclic tetramer having a boiling pointof 110°-112° C. at 3.0 mm. mercury pressure.

Reactant (4): Polymeric methylhydrogensiloxane, as the source of theMe(H)SiO_(2/2) units.

The details of the respective preparations of Si--H Fluids VII and VIIIare given hereinbelow.

Preparation of Si--H Fluid VII

A reaction mixture was prepared containing the aforesaid Reactants(1)-(4) in the following amounts:

Reactant (1): 1.14 grams, corresponding to 0.014 mole of the unit, Me₃SiO_(1/2) ;

Reactant (2): 15.54 grams, corresponding to 0.21 mole of the unit, Me₂SiO_(2/2) ;

Reactant (3): 27.6 grams, corresponding to 0.21 mole of the unit, Me₂SiO_(2/2), and 0.07 mole of the unit, (NC--C₂ H₄ O--C₃ H₆)(Me)SiO_(2/2); and

Reactant (4): 2.52 grams, corresponding to 0.042 mole of the unit,Me(H)SiO_(2/2).

Also added was concentrated (98 percent) sulfuric acid in a total amountof about 1.5 grams. The reaction mixture was stirred at room temperaturefor about 22 hours. The equilibrated reaction product was neutralizedwith excess sodium bicarbonate, treated with filter aid (HyfloSuper-Cel) and charcoal (Darco G-60), followed by pressure filtrationand vacuum stripping of toluene which had been added during filtration.The residual liquid product (32.7 grams) had a Brookfield viscosity of270 centiposie and an average molecular weight of 8600 as determined byGel Permeation Chromatrography (G.P.C.). Upon analysis for Si--Hcontent, the product provided 20.2 cc. H₂ /gram. Based upon theproportions of reactants employed, normalized to two moles of Me₃SiO_(1/2) endblocking units, the average composition of the equilibratedliquid product is expressed as follows, ##STR57## This product isreferred to herein as Si--H Fluid VII.

Preparation of Si--H Fluid VIII

A reaction mixture was prepared containing the aforesaid Reactants(1)-(4) in the following amounts:

Reactant (1): 0.8 grams, corresponding to about 0.01 mole of the unit,Me₃ SiO_(1/2) ;

Reactant (2): 10.4 grams, corresponding to 0.14 mole of the unit, Me₂SiO_(2/2) ;

Reactant (3): 27.6 grams, corresponding to 0.21 mole of the unit, Me₂SiO_(2/2), and 0.07 mole of the unit, (NC--C₂ H₄ O--C₃ H₆)(Me)SiO_(2/2); and

Reactant (4): 2.3 grams, corresponding to about 0.04 mole of the unit,Me(H)SiO_(2/2).

The reaction mixture was stirred at room temperature for about 22 hoursin the presence of about 1.5 grams of concentrated sulfuric aicd. Theequilibrated product was then neutralized with excess sodiumbicarbonate, treated with filter aid and charcoal, followed by pressurefiltration and vacuum stripping of toluene which had been added duringfiltration. The residual liquid product (23.6 grams) had a Brookfieldviscosity of 400 centipoise and an average molecular weight of 11,000(G.P.C.). Upon analysis for Si--H content, the product provided 21.3 cc.H₂ /gram. Based upon the proportions of reactants employed, normalizedto two moles of Me₃ SiO_(1/2) endblocking units, the average compositionof the equilibrated liquid product is as follows, ##STR58## This productis referred to herein as Si--H Fluid VIII.

EXAMPLE 38 PREPARATION OF SURFACTANT J

In a 250 ml. reaction vessel fitted with a mechanical stirrer,thermometer, condenser and nitrogen blow-by, there were combined 20grams of above-described Si--H Fluid VII, 67.3 grams of Polyether C and40 grams of toulene. After heating the reaction mixture to 84° C., therewas then added 0.3 ml. of platinum catalyst prepared by the reaction ofchloroplatinic acid and octyl alcohol. After about 15 minutes of heatingat 84° -86° C., residual Si--H was less than 0.1 cc. H₂ per 0.5 ml.sample. The reaction product was cooled, treated with sodiumbicarbonate, filter aid and charcoal, and was then pressure filtered andvacuum stripped. The liquid reaction product designated herein asSurfactant J, had a viscosity of 2100 centipoise, and average molecularweight of 25,000 (G.P.C.), and is assigned the following averagecomposition, ##STR59##

EXAMPLE 39 PREPARATION OF SURFACTANT K

The copolymer of this example was prepared and worked-up substantiallyas described under Example 38 employing 15 grams of Si--H Fluid VIII and53.5 grams of Polyether C in 40 grams of toluene. The liquid reactionproduct which is referred to herein as Surfactant K, had a viscosity of2300 centipoise, an average molecular weight of 33,000 (G.P.C.), and isassigned the following average composition, ##STR60##

EXAMPLES 40-41

In accordance with these examples, flame-retarded, flexible polyetherpolyol urethane foams were prepared employing Surfactants J and K as therespective foam stabilizers. In addition to the surfactant, the othercomponents of the foam-producing reaction mixture (Foam Formulation C)were as identified in the following Table X.

                  TABLE X                                                         ______________________________________                                        FOAM FORMULATION C                                                                                       Parts By                                           Components                 Weight                                             ______________________________________                                        Polyether Polyol having a Hydroxyl Number                                                                100                                                of about 46 produced by reacting glycerol,                                    propylene oxide and ethylene oxide.                                           Tolylene Diisocyanate (Index 105).sup.1                                                                  48.4                                               Water                      4                                                  Bis[2-(N,N-dimethylamino)ethyl] ether                                                                    0.1                                                employed as a 70 weight percent                                               solution in dipropylene glycol                                                Stannous Octoate           0.25                                               Tris(2,3-dichloropropyl)phosphate                                                                        12.5                                               Surfactant                 0.6                                                ______________________________________                                         .sup.1 As identified in footnote .sup.1 of Table II                      

In these foam preparations, the above-described general foamingprocedure was followed. The results are given in the following Table XI.

                  TABLE XI                                                        ______________________________________                                        Example             40          41                                            ______________________________________                                        Surfactant          J           K                                             Rise, inches        7.0         7.0                                           Breathability, SCFM 3.4         2.6                                           Burning extent, inches                                                                            2.0         1.8                                           Burning time, seconds                                                                             41.1        38.3                                          ______________________________________                                    

EXAMPLES 42-43

In accordance with these examples, a potency determination was made ofSurfactants J and K. In addition to the surfactant, the other componentsof the foam-producing reaction mixture (Foam Formulation D) were asidentified in the following Table XII.

                  TABLE XII                                                       ______________________________________                                        FOAM FORMULATION D                                                                                      Parts By                                            Component                 Weight                                              ______________________________________                                        Polyether Polyol having a Hydroxyl No.                                                                   100                                                of about 46, produced from glycerol,                                          propylene glycol, propylene oxide                                             and ethylene oxide.                                                           Tolylene Diisocyanate.sup.1                                                                              57                                                 Blowing Agent                                                                 Water                      4.85                                               Trichlorofluoromethane     15.0                                               Dimethylethanolamine       0.35                                               Stannous octoate           0.3                                                Surfactant                 0.6                                                ______________________________________                                         .sup.1 As defined in footnote .sup.1 of Table II.                        

As a control foam (Run K-11), above-identified Surfactant BB wasemployed as the surfactant component of Foam Formulation D at aconcentration of 0.6 part per 100 parts of the polyether polyolreactant. The results of these foam preparations are given in Table XIIIwhich follows.

                  TABLE XIII                                                      ______________________________________                                        Example          --         42       43                                       ______________________________________                                        Control          K-11       --       --                                       Surfactant       BB         J        K                                        Rise, inches     11.5       11.7     11.6                                     Breathability, SCFM                                                                            5.0        5.3      3.7                                      ______________________________________                                    

The results of Tables XI and XIII further illustrate the effectivenessof the copolymes of this invention as stabilizers of both flame-retardedand non flame-retarded flexible polyether polyol urethane foam.

1. A process for producing flexible polyurethane foam which comprisessimultaneously reacting and foaming a reaction mixture containing: (a) apolyether polyol reactant containing an average of at least two hydroxylgroups per molecule; (b) a polyisocyanate reactant containing at leasttwo isocyanato groups per molecule; (c) a blowing agent; (d) a catalystcomprising an amine; and (e) a foam stabilizer comprisingpolysiloxane-polyoxalkylene copolymers having the average composition,##STR61## wherein: R is alkyl having from 1 to 10 carbon atoms; Q is acyano-bearing ether group having the formula, --(O)_(q) R'OR"CN, where qis zero or one, R" is bivalent alkylene of 3 to 8 carbon atoms and R" isbivalent alkylene of 2 to 4 carbon atoms; E is a polyoxyalkylene blockhaving the formula, --(R°)_(p) --(OC_(a) H_(2a))_(b) --OG, where R°comprises a bivalent alkylene group a carbon atom of which is bonded tosilicon, G comprises a monovalent hydrocarbon group having from 1 to 12carbon atoms, p is zero or one, a has a value from 2 to 4 provided fromabout 20 to about 65 weight percent of the polyoxyalkylene chain,--(OC_(a) H_(2a))_(b) --, is constituted of oxyethylene units, and b hasan average value such that the average molecular weight of the chain isfrom about 1000 to about 6000; each of t, u, v and w is independentlyzero or one provided each of the sums t+u and v+w is independently zeroor one; each of the sums t+w and u+v is independently zero, one or two;x has an average value from about 10 to about 200; y has an averagevalue from about 2 to about 100; and z has an average value from about 2to about
 30. 2. A process as defined in claim 1 in which said reactionmixture contains a flame-retardant as an additional component thereof.3. A process which comprises simultaneously reacting and foaming areaction mixture containing: (a) a polyether polyol reactant containingan average of at least two hydroxyl groups per molecule; (b) an organicpolyisocyanate reactant containing at least two isocyanato groups permolecule; (c) water as a source of blowing action; (d) a catalystcomprising a tertiary-amine; (e) a flame-retarding agent; and (f) a foamstabilizer comprising siloxane-polyoxyalkylene copolymers having theaverage composition, ##STR62## wherein: R is alkyl having from one tofour carbon atoms; R' is bivalent alkylene of 2 to 6 carbon atoms; R" isbivalent alkylene of 2 to 4 carbon atoms; R° comprises a bivalentalkylene group of from 2 to 6 carbon atoms a carbon atom of which isbonded to silicon; G comprises a monovalent hydrocarbon group havingfrom 1 to 12 carbon atoms; q is zero or one; p is zero or one; x has anaverage value from about 10 to about 200, y has an average value fromabout 2 to about 100, and z has an average value from about 2 to about30, provided an average of from about 55 to about 85 weight percent ofsaid copolymers is constituted of said --(R°)_(p) (OC₂ H₄)_(n) (OC₃H₆)_(m) OG blocks; and m and n are numbers such that the averagemolecular weight of the chain, --(OC₂ H₄)_(n) (OC₃ H₆)_(m) --, is fromabout 1000 to about 6000 and from about 20 to about 65 weight percent ofthe chain is constituted of oxyethylene.
 4. A process for producingflexible polyurethane foam which comprises simultaneously reacting andfoaming a reaction mixture containing: (a) a polyether polyol reactantcontaining an average of at least two hydroxyl groups per molecule; (b)an organic polyisocyanate reactant containing at least two isocyanatogroups per molecule; (c) water as a source of blowing action; (d) acatalyst comprising a tertiary-amine; (e) a flame-retarding agent; and(f) a foam stabilizer comprising siloxane-polyoxyalkylene copolymershaving the average composition, ##STR63## wherein: Me is methyl; R°° isa monovalent hydrocarbon group having from 1 to 12 carbon atoms; x hasan average value from about 20 to about 100, y has an average value fromabout 3 to about 30, and z has an average value from about 2 to about10, provided the average weight of said copolymers attributable to said--C₃ H₆ (OC₂ H₄)_(n) (OC₃ H₆)_(m) OR°° groupings is from about 55 toabout 85 weight percent; and m and n are numbers such that the averagemolecular weight of the chain, --(OC₂ H₄)_(n) (OC₃ H₆)_(m) --, is fromabout 1000 to about 6000 and from about 20 to about 65 weight percent ofsaid chain is constituted of oxyethylene.
 5. A process as defined inclaim 4 in which R°° of said copolymers is methyl.